CData Cloud offers access to Apache Impala across several standard services and protocols, in a cloud-hosted solution. Any application that can connect to a MySQL or SQL Server database can connect to Apache Impala through CData Cloud.
CData Cloud allows you to standardize and configure connections to Apache Impala as though it were any other OData endpoint, or standard SQL Server/MySQL database.
This page provides a guide to Establishing a Connection to Apache Impala in CData Cloud, as well as information on the available resources, and a reference to the available connection properties.
Establishing a Connection shows how to authenticate to Apache Impala and configure any necessary connection properties to create a database in CData Cloud
Accessing data from Apache Impala through the available standard services and CData Cloud administration is documented in further details in the CData Cloud Documentation.
Connect to Apache Impala by selecting the corresponding icon in the Database tab. Required properties are listed under Settings. The Advanced tab lists connection properties that are not typically required.
In order to connect to Apache Impala, set the following:
When QueryPassthrough is set to false (default), the CData ADO.NET Provider for Apache Impala will attempt to modify the query to conform to Impala required format.
There are several ways to authenticate to Apache Impala including:
When using NoSasl, no authentication is performed. It is used when you are connecting to a server from a trusted location such as a test machine on your local network. By default, NoSasl is as the default AuthScheme, so no additional connection properties need to be set.
To authenticate with LDAP, set the following connection properties:
Set the AuthScheme property to Kerberos. Please see Using Kerberos for details about how to authenticate with Kerberos.
This section shows how to use the Cloud to authenticate using Kerberos.
To authenticate to Apache Impala using Kerberos, set the following properties:
You can use one of the following options to retrieve the required Kerberos ticket.
This option enables you to use the MIT Kerberos Ticket Manager or kinit command to get tickets. Note that you do not need to set the User or Password connection properties with this option.
As an alternative to setting the KRB5CCNAME environment variable, you can directly set the file path using the KerberosTicketCache property. When set, the Cloud uses the specified cache file to obtain the Kerberos ticket to connect to Apache Impala.
If the KRB5CCNAME environment variable has not been set, you can retrieve a Kerberos ticket using a Keytab File. To do so, set the User property to the desired username and set the KerberosKeytabFile property to a file path pointing to the keytab file associated with the user.
If both the KRB5CCNAME environment variable and the KerberosKeytabFile property have not been set, you can retrieve a ticket using a user and password combination. To do this, set the User and Password properties to the user/password combination that you use to authenticate with Apache Impala.
More complex Kerberos environments may require cross-realm authentication where multiple realms and KDC servers are used (e.g., where one realm/KDC is used for user authentication and another realm/KDC is used for obtaining the service ticket).
In such an environment, set the KerberosRealm and KerberosKDC properties to the values required for user authentication. Also set the KerberosServiceRealm and KerberosServiceKDC properties to the values required to obtain the service ticket.
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This section details a selection of advanced features of the Apache Impala Cloud.
The Cloud allows you to define virtual tables, called user defined views, whose contents are decided by a pre-configured query. These views are useful when you cannot directly control queries being issued to the drivers. See User Defined Views for an overview of creating and configuring custom views.
Use SSL Configuration to adjust how Cloud handles TLS/SSL certificate negotiations. You can choose from various certificate formats; see the SSLServerCert property under "Connection String Options" for more information.
Configure the Cloud for compliance with Firewall and Proxy, including Windows proxies and HTTP proxies. You can also set up tunnel connections.
The Cloud offloads as much of the SELECT statement processing as possible to Apache Impala and then processes the rest of the query in memory (client-side).
See Query Processing for more information.
See Logging for an overview of configuration settings that can be used to refine CData logging. For basic logging, you only need to set two connection properties, but there are numerous features that support more refined logging, where you can select subsets of information to be logged using the LogModules connection property.
The CData Cloud allows you to define a virtual table whose contents are decided by a pre-configured query. These are called User Defined Views, which are useful in situations where you cannot directly control the query being issued to the driver, e.g. when using the driver from a tool. The User Defined Views can be used to define predicates that are always applied. If you specify additional predicates in the query to the view, they are combined with the query already defined as part of the view.
There are two ways to create user defined views:
You can also have multiple view definitions and control them using the UserDefinedViews connection property. When you use this property, only the specified views are seen by the Cloud.
This User Defined View configuration file is formatted as follows:
For example:
{
"MyView": {
"query": "SELECT * FROM [CData].[Default].Customers WHERE MyColumn = 'value'"
},
"MyView2": {
"query": "SELECT * FROM MyTable WHERE Id IN (1,2,3)"
}
}
Use the UserDefinedViews connection property to specify the location of your JSON configuration file. For example:
"UserDefinedViews", "C:\\Users\\yourusername\\Desktop\\tmp\\UserDefinedViews.json"
SELECT * FROM Customers WHERE City = 'Raleigh';An example of a query to the driver:
SELECT * FROM UserViews.RCustomers WHERE Status = 'Active';Resulting in the effective query to the source:
SELECT * FROM Customers WHERE City = 'Raleigh' AND Status = 'Active';That is a very simple example of a query to a User Defined View that is effectively a combination of the view query and the view definition. It is possible to compose these queries in much more complex patterns. All SQL operations are allowed in both queries and are combined when appropriate.
By default, the Cloud attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store.
To specify another certificate, see the SSLServerCert property for the available formats to do so.
To connect through the Windows system proxy, you do not need to set any additional connection properties. To connect to other proxies, set ProxyAutoDetect to false.
In addition, to authenticate to an HTTP proxy, set ProxyAuthScheme, ProxyUser, and ProxyPassword, in addition to ProxyServer and ProxyPort.
Set the following properties:
For sources that do not support SQL-92, the Cloud offloads as much of SQL statement processing as possible to Apache Impala and then processes the rest of the query in memory (client-side). This results in optimal performance.
For data sources with limited query capabilities, the Cloud handles transformations of the SQL query to make it simpler for the Cloud. The goal is to make smart decisions based on the query capabilities of the data source to push down as much of the computation as possible. The Apache Impala Query Evaluation component examines SQL queries and returns information indicating what parts of the query the Cloud is not capable of executing natively.
The Apache Impala Query Slicer component is used in more specific cases to separate a single query into multiple independent queries. The client-side Query Engine makes decisions about simplifying queries, breaking queries into multiple queries, and pushing down or computing aggregations on the client-side while minimizing the size of the result set.
There's a significant trade-off in evaluating queries, even partially, client-side. There are always queries that are impossible to execute efficiently in this model, and some can be particularly expensive to compute in this manner. CData always pushes down as much of the query as is feasible for the data source to generate the most efficient query possible and provide the most flexible query capabilities.
Capturing Cloud logging can be very helpful when diagnosing error messages or other unexpected behavior.
You will simply need to set two connection properties to begin capturing Cloud logging.
Once this property is set, the Cloud will populate the log file as it carries out various tasks, such as when authentication is performed or queries are executed. If the specified file doesn't already exist, it will be created.
The verbosity level determines the amount of detail that the Cloud reports to the Logfile. Verbosity levels from 1 to 5 are supported. These are described in the following list:
| 1 | Setting Verbosity to 1 will log the query, the number of rows returned by it, the start of execution and the time taken, and any errors. |
| 2 | Setting Verbosity to 2 will log everything included in Verbosity 1 and additional information about the request. |
| 3 | Setting Verbosity to 3 will additionally log HTTP headers, as well as the body of the request and the response. |
| 4 | Setting Verbosity to 4 will additionally log transport-level communication with the data source. This includes SSL negotiation. |
| 5 | Setting Verbosity to 5 will additionally log communication with the data source and additional details that may be helpful in troubleshooting problems. This includes interface commands. |
The Verbosity should not be set to greater than 1 for normal operation. Substantial amounts of data can be logged at higher verbosities, which can delay execution times.
To refine the logged content further by showing/hiding specific categories of information, see LogModules.
Best Practices for Data Security
Although we mask sensitive values, such as passwords, in the connection string and any request in the log, it is always best practice to review the logs for any sensitive information before sharing outside your organization.
You may want to refine the exact information that is recorded to the log file. This can be accomplished using the LogModules property.
This property allows you to filter the logging using a semicolon-separated list of logging modules.
All modules are four characters long. Please note that modules containing three letters have a required trailing blank space. The available modules are:
LogModules=INFO;EXEC;SSL ;SQL ;META;
Note that these modules refine the information as it is pulled after taking the Verbosity into account.
The CData Cloud supports several operations on data, including querying, deleting, modifying, and inserting.
See SELECT Statements for a syntax reference and examples.
See Data Model for information on the capabilities of the Apache Impala API.
See INSERT Statements for a syntax reference and examples.
Use EXECUTE or EXEC statements to execute stored procedures. See EXECUTE Statements for a syntax reference and examples.
A SELECT statement can consist of the following basic clauses.
The following syntax diagram outlines the syntax supported by the SQL engine of the Cloud:
SELECT {
[ TOP <numeric_literal> | DISTINCT ]
{
*
| {
<expression> [ [ AS ] <column_reference> ]
| { <table_name> | <correlation_name> } .*
} [ , ... ]
}
[ INTO csv:// [ filename= ] <file_path> [ ;delimiter=tab ] ]
{
FROM <table_reference> [ [ AS ] <identifier> ]
} [ , ... ]
[ [
INNER | { { LEFT | RIGHT | FULL } [ OUTER ] }
] JOIN <table_reference> [ ON <search_condition> ] [ [ AS ] <identifier> ]
] [ ... ]
[ WHERE <search_condition> ]
[ GROUP BY <column_reference> [ , ... ]
[ HAVING <search_condition> ]
[ UNION [ ALL ] <select_statement> ]
[
ORDER BY
<column_reference> [ ASC | DESC ] [ NULLS FIRST | NULLS LAST ]
]
[
LIMIT <expression>
[
{ OFFSET | , }
<expression>
]
]
} | SCOPE_IDENTITY()
<expression> ::=
| <column_reference>
| @ <parameter>
| ?
| COUNT( * | { [ DISTINCT ] <expression> } )
| { AVG | MAX | MIN | SUM | COUNT } ( <expression> )
| NULLIF ( <expression> , <expression> )
| COALESCE ( <expression> , ... )
| CASE <expression>
WHEN { <expression> | <search_condition> } THEN { <expression> | NULL } [ ... ]
[ ELSE { <expression> | NULL } ]
END
| <literal>
| <sql_function>
<search_condition> ::=
{
<expression> { = | > | < | >= | <= | <> | != | LIKE | NOT LIKE | IN | NOT IN | IS NULL | IS NOT NULL | AND | OR | CONTAINS | BETWEEN } [ <expression> ]
} [ { AND | OR } ... ]
SELECT * FROM [CData].[Default].Customers
SELECT [CompanyName] AS MY_CompanyName FROM [CData].[Default].Customers
SELECT CAST(Balance AS VARCHAR) AS Str_Balance FROM [CData].[Default].Customers
SELECT * FROM [CData].[Default].Customers WHERE Country = 'US'
SELECT COUNT(*) AS MyCount FROM [CData].[Default].Customers
SELECT COUNT(DISTINCT CompanyName) FROM [CData].[Default].Customers
SELECT DISTINCT CompanyName FROM [CData].[Default].Customers
SELECT CompanyName, MAX(Balance) FROM [CData].[Default].Customers GROUP BY CompanyNameSee Aggregate Functions for details.
SELECT Customers.ContactName, Orders.OrderDate FROM Customers, Orders WHERE Customers.CustomerId=Orders.CustomerIdSee JOIN Queries for details.
SELECT City, CompanyName FROM [CData].[Default].Customers ORDER BY CompanyName ASC
SELECT City, CompanyName FROM [CData].[Default].Customers LIMIT 10
SELECT * FROM [CData].[Default].Customers WHERE Country = @param
Some input-only fields are available in SELECT statements. These fields, called pseudo columns, do not
appear as regular columns in the results, yet may be specified as part of the WHERE clause. You can use pseudo columns to access additional features from Apache Impala.
SELECT * FROM [CData].[Default].Customers WHERE MyPseudocolumn = 'MyValue'
Returns the number of rows matching the query criteria.
SELECT COUNT(*) FROM [CData].[Default].Customers WHERE Country = 'US'
Returns the number of distinct, non-null field values matching the query criteria.
SELECT COUNT(DISTINCT City) AS DistinctValues FROM [CData].[Default].Customers WHERE Country = 'US'
Returns the average of the column values.
SELECT CompanyName, AVG(Balance) FROM [CData].[Default].Customers WHERE Country = 'US' GROUP BY CompanyName
Returns the minimum column value.
SELECT MIN(Balance), CompanyName FROM [CData].[Default].Customers WHERE Country = 'US' GROUP BY CompanyName
Returns the maximum column value.
SELECT CompanyName, MAX(Balance) FROM [CData].[Default].Customers WHERE Country = 'US' GROUP BY CompanyName
Returns the total sum of the column values.
SELECT SUM(Balance) FROM [CData].[Default].Customers WHERE Country = 'US'
The CData Cloud supports standard SQL joins like the following examples.
An inner join selects only rows from both tables that match the join condition:
SELECT Customers.ContactName, Orders.OrderDate FROM Customers, Orders WHERE Customers.CustomerId=Orders.CustomerId
A left join selects all rows in the FROM table and only matching rows in the JOIN table:
SELECT Customers.ContactName, Orders.OrderDate FROM Customers LEFT OUTER JOIN Orders ON Customers.CustomerId=Orders.CustomerId
The following date literal functions can be used to filter date fields using relative intervals. Note that while the <, >, and = operators are supported for these functions, <= and >= are not.
The current day.
SELECT * FROM MyTable WHERE MyDateField = L_TODAY()
The previous day.
SELECT * FROM MyTable WHERE MyDateField = L_YESTERDAY()
The following day.
SELECT * FROM MyTable WHERE MyDateField = L_TOMORROW()
Every day in the preceding week.
SELECT * FROM MyTable WHERE MyDateField = L_LAST_WEEK()
Every day in the current week.
SELECT * FROM MyTable WHERE MyDateField = L_THIS_WEEK()
Every day in the following week.
SELECT * FROM MyTable WHERE MyDateField = L_NEXT_WEEK()Also available:
The previous n days, excluding the current day.
SELECT * FROM MyTable WHERE MyDateField = L_LAST_N_DAYS(3)
The following n days, including the current day.
SELECT * FROM MyTable WHERE MyDateField = L_NEXT_N_DAYS(3)Also available:
Every day in every week, starting n weeks before current week, and ending in the previous week.
SELECT * FROM MyTable WHERE MyDateField = L_LAST_N_WEEKS(3)
Every day in every week, starting the following week, and ending n weeks in the future.
SELECT * FROM MyTable WHERE MyDateField = L_NEXT_N_WEEKS(3)Also available:
Returns expr rounded to d decimal places using HALF_UP rounding mode.
Returns expr rounded to d decimal places using HALF_EVEN rounding mode.
Returns the largest integer not greater than expr.
Returns the smallest integer not smaller than expr.
Returns a random value with independent and identically distributed (i.i.d.) uniformly distributed values in [0, 1).
Returns e to the power of expr.
Returns the natural logarithm (base e) of expr.
Returns the logarithm of expr with base 10.
Returns the logarithm of expr with base 2.
Returns the logarithm of expr with base.
Raises expr1 to the power of expr2.
Returns the square root of expr.
Returns the string representation of the long value expr represented in binary.
Converts expr to hexadecimal.
Converts hexadecimal expr to binary.
Convert num from from_base to to_base.
Returns the absolute value of the numeric value.
Returns the positive value of expr1 mod expr2.
Returns the sine of expr, as if computed by java.lang.Math.sin.
Returns the inverse sine (a.k.a. arc sine) the arc sin of expr, as if computed by java.lang.Math.asin.
Returns the cosine of expr, as if computed by java.lang.Math.cos.
Returns the inverse cosine (a.k.a. arc cosine) of expr, as if computed by java.lang.Math.acos.
Returns the tangent of expr, as if computed by java.lang.Math.tan.
Returns the inverse tangent (a.k.a. arc tangent) of expr, as if computed by java.lang.Math.atan
Converts radians to degrees.
Converts degrees to radians.
Returns the postive value of expr.
Returns the negated value of expr.
Returns -1.0, 0.0 or 1.0 as expr is negative, 0 or positive.
Returns Euler's number, e.
Returns pi.
Returns the factorial of expr. expr is [0..20]. Otherwise, null.
Returns the cube root of expr.
Bitwise left shift.
Bitwise right shift.
Bitwise unsigned right shift.
Returns the greatest value of all parameters, skipping null values.
Returns the least value of all parameters, skipping null values.
Returns an integer between 0 and num_buckets+1 by mapping expr into the ith equally sized bucket. Buckets are made by dividing [min_value, max_value] into equally sized regions. If expr < min_value, return 1, if expr > max_value return num_buckets+1.
Returns the size of an array or a map. Returns -1 if null.
Returns an unordered array containing the keys of the map.
Returns an unordered array containing the values of the map.
Returns true if the array contains the value.
Sorts the input array in ascending or descending order according to the natural ordering of the array elements.
Casts the value expr to the target data type binary.
Casts the value expr to the target data type type.
Returns the UNIX timestamp of the given time.
Parses the date_str expression with the fmt expression to a date. Returns null with invalid input. By default, it follows casting rules to a date if the fmt is omitted.
Returns the year component of the date/timestamp.
Returns the quarter of the year for date, in the range 1 to 4.
Returns the month component of the date/timestamp.
Returns the day of month of the date/timestamp.
Returns the hour component of the string/timestamp.
Returns the minute component of the string/timestamp.
Returns the second component of the string/timestamp.
Returns the week of the year of the given date. A week is considered to start on a Monday and week 1 is the first week with >3 days.
Returns the number of days from startDate to endDate.
Returns the date that is num_days after start_date.
Returns the date that is num_days before start_date.
Given a timestamp like '2017-07-14 02:40:00.0', interprets it as a time in UTC, and renders that time as a timestamp in the given time zone. For example, 'GMT+1' would yield '2017-07-14 03:40:00.0'.
Given a timestamp like '2017-07-14 02:40:00.0', interprets it as a time in the given time zone, and renders that time as a timestamp in UTC. For example, 'GMT+1' would yield '2017-07-14 01:40:00.0'.
Returns the current date at the start of query evaluation.
Returns the current timestamp at the start of query evaluation.
Returns the date that is num_months after start_date.
Returns the last day of the month which the date belongs to.
Returns the first date which is later than start_date and named as indicated.
Returns date with the time portion of the day truncated to the unit specified by the format model fmt. fmt should be one of ["year", "yyyy", "yy", "mon", "month", "mm"]
Returns number of months between timestamp1 and timestamp2.
Converts timestamp to a value of string in the format specified by the date format fmt.
If expr1 evaluates to true, then returns expr2; otherwise returns expr3.
Returns true if expr is null, or false otherwise.
Returns true if expr is not null, or false otherwise.
Returns expr1 if it's not NaN, or expr2 otherwise.
Returns the first non-null argument if exists. Otherwise, null.
Returns null if expr1 equals to expr2, or expr1 otherwise.
Throws an exception if expr is not true.
Returns the numeric value of the first character of str.
Converts the argument from a binary bin to a base 64 string.
Returns the character length of string data or number of bytes of binary data. The length of string data includes the trailing spaces. The length of binary data includes binary zeros.
Returns the ASCII character having the binary equivalent to expr. If n is larger than 256 the result is equivalent to chr(n % 256)
Returns the concatenation of the strings separated by sep.
Decodes the first argument using the second argument character set.
Returns the n-th input, e.g., returns input2 when n is 2.
Encodes the first argument using the second argument character set.
Returns the index of val in the val1,val2,val3,... list or 0 if not found. For example field('world','say','hello','world') returns 3. All primitive types are supported, arguments are compared using str.equals(x). If val is NULL, the return value is 0.
Returns the index (1-based) of the given string (str) in the comma-delimited list (str_array). Returns 0, if the string was not found or if the given string (str) contains a comma.
Formats the number expr1 like '#,###,###.##', rounded to expr2 decimal places. If expr2 is 0, the result has no decimal point or fractional part. This is supposed to function like MySQL's FORMAT.
Extracts a json object from path.
Returns true if the string str appears as an entire line in filename.
Returns the (1-based) index of the first occurrence of substr in str.
Returns the character length of string data or number of bytes of binary data. The length of string data includes the trailing spaces. The length of binary data includes binary zeros.
Returns the position of the first occurrence of substr in str after position pos. The given pos and return value are 1-based.
Returns str with all characters changed to lowercase.
Returns str, left-padded with pad to a length of len. If str is longer than len, the return value is shortened to len characters.
Removes the leading space characters from str.
Returns the byte length of expr or number of bytes in binary data.
Returns the specified part from the URL. For example, parse_url('http://facebook.com/path1/p.php?k1=v1#Ref1', 'HOST') returns 'facebook.com'. Also a value of a particular key in QUERY can be extracted by providing the key as the third argument, for example, parse_url('http://facebook.com/path1/p.php?k1=v1#Ref1', 'QUERY', 'k1') returns 'v1'.
Returns a formatted string from printf-style format strings.
Extracts a group that matches regexp.
Replaces all substring of str that match regexp with rep.
Returns the string which repeats the given string value n times.
Replaces all occurrences of search with replace. If search is not found in str, str is returned unchanged. If replace is not specified or is an empty string, nothing replaces the string that is removed from str.
Returns the reversed given string.
Returns str, right-padded with pad to a length of len. If str is longer than len, the return value is shortened to len characters.
Removes the trailing space characters from str.
Splits str into an array of array of words.
Returns a string consisting of n spaces.
Splits str around occurrences that match regex.
Creates a map after splitting the text into key/value pairs using delimiters. Default delimiters are ',' for pairDelim and ':' for keyValueDelim.
Returns the substring of str that starts at pos and is of length len, or the slice of byte array that starts at pos and is of length len.
Returns the substring from str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is returned. The function substring_index performs a case-sensitive match when searching for delim.
Translates the input string by replacing the characters present in the from string with the corresponding characters in the to string.
Removes the leading and trailing space characters from str.
Converts the argument from a base 64 string str to a binary.
Returns str with all characters changed to uppercase.
Returns str with the first letter of each word in uppercase. All other letters are in lowercase. Words are delimited by white space.
Returns the Levenshtein distance between the two given strings.
Returns Soundex code of the string.
Returns a masked version of str. By default, upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example mask("abcd-EFGH-8765-4321") results in xxxx-XXXX-nnnn-nnnn. You can override the characters used in the mask by supplying additional arguments: the second argument controls the mask character for upper case letters, the third argument for lower case letters and the fourth argument for numbers. For example, mask("abcd-EFGH-8765-4321", "U", "l", "#") results in llll-UUUU-####-####.
Returns a masked version of str with the first n values masked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_first_n("1234-5678-8765-4321", 4) results in nnnn-5678-8765-4321.
Returns a masked version of str with the last n values masked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_last_n("1234-5678-8765-4321", 4) results in 1234-5678-8765-nnnn.
Returns a masked version of str, showing the first n characters unmasked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_show_first_n("1234-5678-8765-4321", 4) results in 1234-nnnn-nnnn-nnnn.
Returns a masked version of str, showing the last n characters unmasked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_show_last_n("1234-5678-8765-4321", 4) results in nnnn-nnnn-nnnn-4321.
Returns a hashed value based on str. The hash is consistent and can be used to join masked values together across tables. This function returns null for non-string types.
Calls a method with reflection.
Calls a method with reflection.
Returns a hash value of the arguments.
Returns current user name from the configured authenticator manager. Could be the same as the user provided when connecting, but with some authentication managers (for example HadoopDefaultAuthenticator) it could be different.
Returns current user name from the session state. This is the username provided when connecting to Impala.
Returns current database name.
Returns an MD5 128-bit checksum as a hex string of expr.
Returns a sha1 hash value as a hex string of the expr.
Returns a cyclic redundancy check value of the expr as a bigint.
Returns a checksum of SHA-2 family as a hex string of expr. SHA-224, SHA-256, SHA-384, and SHA-512 are supported. Bit length of 0 is equivalent to 256.
Encrypt input using AES. Key lengths of 128, 192 or 256 bits can be used. 192 and 256 bits keys can be used if Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files are installed. If either argument is NULL or the key length is not one of the permitted values, the return value is NULL. Example: base64(aes_encrypt('ABC', '1234567890123456')) = 'y6Ss+zCYObpCbgfWfyNWTw=='.
Returns the Impala version. The string contains 2 fields, the first being a build number and the second being a build hash. Example: "select version();" might return "2.1.0.2.5.0.0-1245 r027527b9c5ce1a3d7d0b6d2e6de2378fb0c39232". Actual results will depend on your build.
Returns the number of rows for which the supplied expression(s) are unique and non-null.
Returns the sum calculated from values of a group.
Returns the sum calculated from distinct values of a group.
Returns the mean calculated from values of a group.
Returns the mean calculated from distinct values of a group.
Returns the minimum value of expr.
Returns the maximum value of expr.
Returns the sample variance calculated from values of a group.
Returns the population standard deviation calculated from values of a group.
Returns the sample standard deviation calculated from values of a group.
Returns the population covariance of a set of number pairs.
Returns the sample covariance of a set of number pairs.
Returns Pearson coefficient of correlation between a set of number pairs.
Returns the exact percentile value of numeric column col at the given percentage. The value of percentage must be between 0.0 and 1.0. The value of frequency should be positive integral
Returns the approximate percentile value of numeric column col at the given percentage. The value of percentage must be between 0.0 and 1.0. The accuracy parameter (default: 10000) is a positive numeric literal which controls approximation accuracy at the cost of memory. Higher value of accuracy yields better accuracy, 1.0/accuracy is the relative error of the approximation. When percentage is an array, each value of the percentage array must be between 0.0 and 1.0. In this case, returns the approximate percentile array of column col at the given percentage array.
Collects and returns a set of unique elements.
Collects and returns a set of unique elements.
Divides the rows for each window partition into n buckets ranging from 1 to at most n.
Separates the elements of array expr into multiple rows, or the elements of map expr into multiple rows and columns.
Separates the elements of array expr into multiple rows with positions, or the elements of map expr into multiple rows and columns with positions.
Explodes an array of structs into a table.
Separates expr1, ..., exprk into n rows.
Takes URL string and a set of n URL parts, and returns a tuple of n values. This is similar to the parse_url() UDF but can extract multiple parts at once out of a URL. Valid part names are: HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, USERINFO, QUERY:[KEY].
Returns expr rounded to d decimal places using HALF_UP rounding mode.
Returns expr rounded to d decimal places using HALF_EVEN rounding mode.
Returns the largest integer not greater than expr.
Returns the smallest integer not smaller than expr.
Returns a random value with independent and identically distributed (i.i.d.) uniformly distributed values in [0, 1).
Returns e to the power of expr.
Returns the natural logarithm (base e) of expr.
Returns the logarithm of expr with base 10.
Returns the logarithm of expr with base 2.
Returns the logarithm of expr with base.
Raises expr1 to the power of expr2.
Returns the square root of expr.
Returns the string representation of the long value expr represented in binary.
Converts expr to hexadecimal.
Converts hexadecimal expr to binary.
Convert num from from_base to to_base.
Returns the absolute value of the numeric value.
Returns the positive value of expr1 mod expr2.
Returns the sine of expr, as if computed by java.lang.Math.sin.
Returns the inverse sine (a.k.a. arc sine) the arc sin of expr, as if computed by java.lang.Math.asin.
Returns the cosine of expr, as if computed by java.lang.Math.cos.
Returns the inverse cosine (a.k.a. arc cosine) of expr, as if computed by java.lang.Math.acos.
Returns the tangent of expr, as if computed by java.lang.Math.tan.
Returns the inverse tangent (a.k.a. arc tangent) of expr, as if computed by java.lang.Math.atan
Converts radians to degrees.
Converts degrees to radians.
Returns the postive value of expr.
Returns the negated value of expr.
Returns -1.0, 0.0 or 1.0 as expr is negative, 0 or positive.
Returns Euler's number, e.
Returns pi.
Returns the factorial of expr. expr is [0..20]. Otherwise, null.
Returns the cube root of expr.
Bitwise left shift.
Bitwise right shift.
Bitwise unsigned right shift.
Returns the greatest value of all parameters, skipping null values.
Returns the least value of all parameters, skipping null values.
Returns an integer between 0 and num_buckets+1 by mapping expr into the ith equally sized bucket. Buckets are made by dividing [min_value, max_value] into equally sized regions. If expr < min_value, return 1, if expr > max_value return num_buckets+1.
Returns the size of an array or a map. Returns -1 if null.
Returns an unordered array containing the keys of the map.
Returns an unordered array containing the values of the map.
Returns true if the array contains the value.
Sorts the input array in ascending or descending order according to the natural ordering of the array elements.
Casts the value expr to the target data type binary.
Casts the value expr to the target data type type.
Returns the UNIX timestamp of the given time.
Parses the date_str expression with the fmt expression to a date. Returns null with invalid input. By default, it follows casting rules to a date if the fmt is omitted.
Returns the year component of the date/timestamp.
Returns the quarter of the year for date, in the range 1 to 4.
Returns the month component of the date/timestamp.
Returns the day of month of the date/timestamp.
Returns the hour component of the string/timestamp.
Returns the minute component of the string/timestamp.
Returns the second component of the string/timestamp.
Returns the week of the year of the given date. A week is considered to start on a Monday and week 1 is the first week with >3 days.
Returns the number of days from startDate to endDate.
Returns the date that is num_days after start_date.
Returns the date that is num_days before start_date.
Given a timestamp like '2017-07-14 02:40:00.0', interprets it as a time in UTC, and renders that time as a timestamp in the given time zone. For example, 'GMT+1' would yield '2017-07-14 03:40:00.0'.
Given a timestamp like '2017-07-14 02:40:00.0', interprets it as a time in the given time zone, and renders that time as a timestamp in UTC. For example, 'GMT+1' would yield '2017-07-14 01:40:00.0'.
Returns the current date at the start of query evaluation.
Returns the current timestamp at the start of query evaluation.
Returns the date that is num_months after start_date.
Returns the last day of the month which the date belongs to.
Returns the first date which is later than start_date and named as indicated.
Returns date with the time portion of the day truncated to the unit specified by the format model fmt. fmt should be one of ["year", "yyyy", "yy", "mon", "month", "mm"]
Returns number of months between timestamp1 and timestamp2.
Converts timestamp to a value of string in the format specified by the date format fmt.
If expr1 evaluates to true, then returns expr2; otherwise returns expr3.
Returns true if expr is null, or false otherwise.
Returns true if expr is not null, or false otherwise.
Returns expr1 if it's not NaN, or expr2 otherwise.
Returns the first non-null argument if exists. Otherwise, null.
Returns null if expr1 equals to expr2, or expr1 otherwise.
Throws an exception if expr is not true.
Returns the numeric value of the first character of str.
Converts the argument from a binary bin to a base 64 string.
Returns the character length of string data or number of bytes of binary data. The length of string data includes the trailing spaces. The length of binary data includes binary zeros.
Returns the ASCII character having the binary equivalent to expr. If n is larger than 256 the result is equivalent to chr(n % 256)
Returns the concatenation of the strings separated by sep.
Decodes the first argument using the second argument character set.
Returns the n-th input, e.g., returns input2 when n is 2.
Encodes the first argument using the second argument character set.
Returns the index of val in the val1,val2,val3,... list or 0 if not found. For example field('world','say','hello','world') returns 3. All primitive types are supported, arguments are compared using str.equals(x). If val is NULL, the return value is 0.
Returns the index (1-based) of the given string (str) in the comma-delimited list (str_array). Returns 0, if the string was not found or if the given string (str) contains a comma.
Formats the number expr1 like '#,###,###.##', rounded to expr2 decimal places. If expr2 is 0, the result has no decimal point or fractional part. This is supposed to function like MySQL's FORMAT.
Extracts a json object from path.
Returns true if the string str appears as an entire line in filename.
Returns the (1-based) index of the first occurrence of substr in str.
Returns the character length of string data or number of bytes of binary data. The length of string data includes the trailing spaces. The length of binary data includes binary zeros.
Returns the position of the first occurrence of substr in str after position pos. The given pos and return value are 1-based.
Returns str with all characters changed to lowercase.
Returns str, left-padded with pad to a length of len. If str is longer than len, the return value is shortened to len characters.
Removes the leading space characters from str.
Returns the byte length of expr or number of bytes in binary data.
Returns the specified part from the URL. For example, parse_url('http://facebook.com/path1/p.php?k1=v1#Ref1', 'HOST') returns 'facebook.com'. Also a value of a particular key in QUERY can be extracted by providing the key as the third argument, for example, parse_url('http://facebook.com/path1/p.php?k1=v1#Ref1', 'QUERY', 'k1') returns 'v1'.
Returns a formatted string from printf-style format strings.
Extracts a group that matches regexp.
Replaces all substring of str that match regexp with rep.
Returns the string which repeats the given string value n times.
Replaces all occurrences of search with replace. If search is not found in str, str is returned unchanged. If replace is not specified or is an empty string, nothing replaces the string that is removed from str.
Returns the reversed given string.
Returns str, right-padded with pad to a length of len. If str is longer than len, the return value is shortened to len characters.
Removes the trailing space characters from str.
Splits str into an array of array of words.
Returns a string consisting of n spaces.
Splits str around occurrences that match regex.
Creates a map after splitting the text into key/value pairs using delimiters. Default delimiters are ',' for pairDelim and ':' for keyValueDelim.
Returns the substring of str that starts at pos and is of length len, or the slice of byte array that starts at pos and is of length len.
Returns the substring from str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is returned. The function substring_index performs a case-sensitive match when searching for delim.
Translates the input string by replacing the characters present in the from string with the corresponding characters in the to string.
Removes the leading and trailing space characters from str.
Converts the argument from a base 64 string str to a binary.
Returns str with all characters changed to uppercase.
Returns str with the first letter of each word in uppercase. All other letters are in lowercase. Words are delimited by white space.
Returns the Levenshtein distance between the two given strings.
Returns Soundex code of the string.
Returns a masked version of str. By default, upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example mask("abcd-EFGH-8765-4321") results in xxxx-XXXX-nnnn-nnnn. You can override the characters used in the mask by supplying additional arguments: the second argument controls the mask character for upper case letters, the third argument for lower case letters and the fourth argument for numbers. For example, mask("abcd-EFGH-8765-4321", "U", "l", "#") results in llll-UUUU-####-####.
Returns a masked version of str with the first n values masked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_first_n("1234-5678-8765-4321", 4) results in nnnn-5678-8765-4321.
Returns a masked version of str with the last n values masked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_last_n("1234-5678-8765-4321", 4) results in 1234-5678-8765-nnnn.
Returns a masked version of str, showing the first n characters unmasked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_show_first_n("1234-5678-8765-4321", 4) results in 1234-nnnn-nnnn-nnnn.
Returns a masked version of str, showing the last n characters unmasked. Upper case letters are converted to "X", lower case letters are converted to "x" and numbers are converted to "n". For example, mask_show_last_n("1234-5678-8765-4321", 4) results in nnnn-nnnn-nnnn-4321.
Returns a hashed value based on str. The hash is consistent and can be used to join masked values together across tables. This function returns null for non-string types.
Calls a method with reflection.
Calls a method with reflection.
Returns a hash value of the arguments.
Returns current user name from the configured authenticator manager. Could be the same as the user provided when connecting, but with some authentication managers (for example HadoopDefaultAuthenticator) it could be different.
Returns current user name from the session state. This is the username provided when connecting to Impala.
Returns current database name.
Returns an MD5 128-bit checksum as a hex string of expr.
Returns a sha1 hash value as a hex string of the expr.
Returns a cyclic redundancy check value of the expr as a bigint.
Returns a checksum of SHA-2 family as a hex string of expr. SHA-224, SHA-256, SHA-384, and SHA-512 are supported. Bit length of 0 is equivalent to 256.
Encrypt input using AES. Key lengths of 128, 192 or 256 bits can be used. 192 and 256 bits keys can be used if Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files are installed. If either argument is NULL or the key length is not one of the permitted values, the return value is NULL. Example: base64(aes_encrypt('ABC', '1234567890123456')) = 'y6Ss+zCYObpCbgfWfyNWTw=='.
Returns the Impala version. The string contains 2 fields, the first being a build number and the second being a build hash. Example: "select version();" might return "2.1.0.2.5.0.0-1245 r027527b9c5ce1a3d7d0b6d2e6de2378fb0c39232". Actual results will depend on your build.
Returns the number of rows for which the supplied expression(s) are unique and non-null.
Returns the sum calculated from values of a group.
Returns the sum calculated from distinct values of a group.
Returns the mean calculated from values of a group.
Returns the mean calculated from distinct values of a group.
Returns the minimum value of expr.
Returns the maximum value of expr.
Returns the sample variance calculated from values of a group.
Returns the population standard deviation calculated from values of a group.
Returns the sample standard deviation calculated from values of a group.
Returns the population covariance of a set of number pairs.
Returns the sample covariance of a set of number pairs.
Returns Pearson coefficient of correlation between a set of number pairs.
Returns the exact percentile value of numeric column col at the given percentage. The value of percentage must be between 0.0 and 1.0. The value of frequency should be positive integral
Returns the approximate percentile value of numeric column col at the given percentage. The value of percentage must be between 0.0 and 1.0. The accuracy parameter (default: 10000) is a positive numeric literal which controls approximation accuracy at the cost of memory. Higher value of accuracy yields better accuracy, 1.0/accuracy is the relative error of the approximation. When percentage is an array, each value of the percentage array must be between 0.0 and 1.0. In this case, returns the approximate percentile array of column col at the given percentage array.
Collects and returns a set of unique elements.
Collects and returns a set of unique elements.
Divides the rows for each window partition into n buckets ranging from 1 to at most n.
Separates the elements of array expr into multiple rows, or the elements of map expr into multiple rows and columns.
Separates the elements of array expr into multiple rows with positions, or the elements of map expr into multiple rows and columns with positions.
Explodes an array of structs into a table.
Separates expr1, ..., exprk into n rows.
Takes URL string and a set of n URL parts, and returns a tuple of n values. This is similar to the parse_url() UDF but can extract multiple parts at once out of a URL. Valid part names are: HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, USERINFO, QUERY:[KEY].
You can use the SELECT INTO statement to export formatted data to a file.
The following query exports data into a file formatted in comma-separated values (CSV):
SELECT City, CompanyName INTO [csv://[CData].[Default].Customers.txt] FROM [[CData].[Default].Customers] WHERE Country = 'US'You can specify other formats in the file URI. The possible delimiters are tab, semicolon, and comma with the default being a comma. The following example exports tab-separated values:
SELECT City, CompanyName INTO [csv://[CData].[Default].Customers.txt;delimiter=tab] FROM [[CData].[Default].Customers] WHERE Country = 'US'You can specify other file formats in the URI. The following example exports tab-separated values:
The Cloud provides functions that are similar to those that are available with most standard databases. These functions are implemented in the CData provider engine and thus are available across all data sources with the same consistent API. Three categories of functions are available: string, date, and math.
The Cloud interprets all SQL function inputs as either strings or column identifiers, so you need to escape all literals as strings, with single quotes. For example, contrast the SQL Server syntax and Cloud syntax for the DATENAME function:
SELECT DATENAME(yy,GETDATE())
SELECT DATENAME('yy',GETDATE())
These functions perform string manipulations and return a string value. See STRING Functions for more details.
SELECT CONCAT(firstname, space(4), lastname) FROM [CData].[Default].Customers WHERE Country = 'US'
These functions perform date and date time manipulations. See DATE Functions for more details.
SELECT CURRENT_TIMESTAMP() FROM [CData].[Default].Customers
These functions provide mathematical operations. See MATH Functions for more details.
SELECT RAND() FROM [CData].[Default].Customers
SELECT CONCAT('Mr.', SPACE(2), firstname, SPACE(4), lastname) FROM [CData].[Default].Customers
These functions can be used to specify criteria in the WHERE clause of your SQL query. See Predicate Functions for more details.
* FROM [CData].[Default].Customers WHERE CreatedDate = NOW()
Returns the ASCII code value of the left-most character of the character expression.
SELECT ASCII('0');
-- Result: 48
Converts the integer ASCII code to the corresponding character.
SELECT CHAR(48);
-- Result: '0'
Returns the starting position of the specified expression in the character string.
SELECT CHARINDEX('456', '0123456');
-- Result: 4
SELECT CHARINDEX('456', '0123456', 5);
-- Result: -1
Returns the number of UTF-8 characters present in the expression.
SELECT CHAR_LENGTH('sample text') FROM Account LIMIT 1
-- Result: 11
Returns the string that is the concatenation of two or more string values.
SELECT CONCAT('Hello, ', 'world!');
-- Result: 'Hello, world!'
Returns 1 if expressionToFind is found within expressionToSearch; otherwise, 0.
SELECT CONTAINS('0123456', '456');
-- Result: 1
SELECT CONTAINS('0123456', 'Not a number');
-- Result: 0
Returns 1 if character_expression ends with character_suffix; otherwise, 0.
SELECT ENDSWITH('0123456', '456');
-- Result: 1
SELECT ENDSWITH('0123456', '012');
-- Result: 0
Returns the number of bytes present in the file at the specified file path.
SELECT FILESIZE('C:/Users/User1/Desktop/myfile.txt');
-- Result: 23684
Returns the value formatted with the specified format.
SELECT FORMAT(12.34, '#');
-- Result: 12
SELECT FORMAT(12.34, '#.###');
-- Result: 12.34
SELECT FORMAT(1234, '0.000E0');
-- Result: 1.234E3
SELECT FORMAT('2019/01/01', 'yyyy-MM-dd');
-- Result: 2019-01-01
SELECT FORMAT('20190101', 'yyyyMMdd', 'yyyy-MM-dd');
-- Result: '2019-01-01'
Returns a representation of the unix_timestamp argument as a value in YYYY-MM-DD HH:MM:SS expressed in the current time zone.
SELECT FROM_UNIXTIME(1540495231, 1);
-- Result: 2018-10-25 19:20:31
SELECT FROM_UNIXTIME(1540495357385, 0);
-- Result: 2018-10-25 19:22:37
Returns the hash of the input value as a byte array using the given algorithm. The supported algorithms are MD5, SHA1, SHA2_256, SHA2_512, SHA3_224, SHA3_256, SHA3_384, and SHA3_512.
SELECT HASHBYTES('MD5', 'Test');
-- Result (byte array): 0x0CBC6611F5540BD0809A388DC95A615B
Returns the starting position of the specified expression in the character string.
SELECT INDEXOF('0123456', '456');
-- Result: 4
SELECT INDEXOF('0123456', '456', 5);
-- Result: -1
Replaces null with the specified replacement value.
SELECT ISNULL(42, 'Was NULL');
-- Result: 42
SELECT ISNULL(NULL, 'Was NULL');
-- Result: 'Was NULL'
Computes the average value of a JSON array within a JSON object. The path to the array is specified in the jsonpath argument. Return value is numeric or null.
SELECT JSON_AVG('[1,2,3,4,5]', '$[x]');
-- Result: 3
SELECT JSON_AVG('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[x]');
-- Result: 3
SELECT JSON_AVG('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[3..]');
-- Result: 4.5
Returns the number of elements in a JSON array within a JSON object. The path to the array is specified in the jsonpath argument. Return value is numeric or null.
SELECT JSON_COUNT('[1,2,3,4,5]', '$[x]');
-- Result: 5
SELECT JSON_COUNT('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[x]');
-- Result: 5
SELECT JSON_COUNT('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[3..]');
-- Result: 2
Selects any value in a JSON array or object. The path to the array is specified in the jsonpath argument. Return value is numeric or null.
SELECT JSON_EXTRACT('{"test": {"data": 1}}', '$.test');
-- Result: '{"data":1}'
SELECT JSON_EXTRACT('{"test": {"data": 1}}', '$.test.data');
-- Result: 1
SELECT JSON_EXTRACT('{"test": {"data": [1, 2, 3]}}', '$.test.data[1]');
-- Result: 2
Gets the maximum value in a JSON array within a JSON object. The path to the array is specified in the jsonpath argument. Return value is numeric or null.
SELECT JSON_MAX('[1,2,3,4,5]', '$[x]');
-- Result: 5
SELECT JSON_MAX('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[x]');
-- Result: 5
SELECT JSON_MAX('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[..3]');
-- Result: 4
Gets the minimum value in a JSON array within a JSON object. The path to the array is specified in the jsonpath argument. Return value is numeric or null.
SELECT JSON_MIN('[1,2,3,4,5]', '$[x]');
-- Result: 1
SELECT JSON_MIN('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[x]');
-- Result: 1
SELECT JSON_MIN('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[3..]');
-- Result: 4
Computes the summary value in JSON according to the JSONPath expression. Return value is numeric or null.
SELECT JSON_SUM('[1,2,3,4,5]', '$[x]');
-- Result: 15
SELECT JSON_SUM('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[x]');
-- Result: 15
SELECT JSON_SUM('{"test": {"data": [1,2,3,4,5]}}', '$.test.data[3..]');
-- Result: 9
Returns the specified number of characters counting from the left of the specified string.
SELECT LEFT('1234567890', 3);
-- Result: '123'
Returns the number of characters of the specified string expression.
SELECT LEN('12345');
-- Result: 5
Returns an integer representing how many characters into the string the substring appears.
SELECT LOCATE('sample','XXXXXsampleXXXXX');
-- Result: 6
Returns the character expression with the uppercase character data converted to lowercase.
SELECT LOWER('MIXED case');
-- Result: 'mixed case'
Returns the character expression with leading blanks removed.
SELECT LTRIM(' trimmed');
-- Result: 'trimmed'
Replaces the characters between start_index and end_index with the mask_character within the string.
SELECT MASK('1234567890','*',);
-- Result: '**********'
SELECT MASK('1234567890','*', 4);
-- Result: '1234******'
SELECT MASK('1234567890','*', 4, 2);
-- Result: '1234****90'
Returns the Unicode character with the specified integer code as defined by the Unicode standard.
Returns the number of bytes present in the expression.
SELECT OCTET_LENGTH('text') FROM Account LIMIT 1
-- Result: 4
Returns the starting position of the first occurrence of the pattern in the expression. Returns 0 if the pattern is not found.
SELECT PATINDEX('123%', '1234567890');
-- Result: 1
SELECT PATINDEX('%890', '1234567890');
-- Result: 8
SELECT PATINDEX('%456%', '1234567890');
-- Result: 4
Returns the starting position of the specified expression in the character string.
SELECT POSITION('456' IN '123456');
-- Result: 4
SELECT POSITION('x' IN '123456');
-- Result: 0
Returns a valid SQL Server-delimited identifier by adding the necessary delimiters to the specified Unicode string.
SELECT QUOTENAME('table_name');
-- Result: '[table_name]'
SELECT QUOTENAME('table_name', '"');
-- Result: '"table_name"'
SELECT QUOTENAME('table_name', '[');
-- Result: '[table_name]'
Replaces all occurrences of a string with another string.
SELECT REPLACE('1234567890', '456', '|');
-- Result: '123|7890'
SELECT REPLACE('123123123', '123', '.');
-- Result: '...'
SELECT REPLACE('1234567890', 'a', 'b');
-- Result: '1234567890'
Repeats the string value the specified number of times.
SELECT REPLACE('x', 5);
-- Result: 'xxxxx'
Returns the reverse order of the string expression.
SELECT REVERSE('1234567890');
-- Result: '0987654321'
Returns the right part of the string with the specified number of characters.
SELECT RIGHT('1234567890', 3);
-- Result: '890'
Returns the character expression after it removes trailing blanks.
SELECT RTRIM('trimmed ');
-- Result: 'trimmed'
Returns the four-character Soundex code, based on how the string sounds when spoken.
SELECT SOUNDEX('smith');
-- Result: 'S530'
Returns the string that consists of repeated spaces.
SELECT SPACE(5);
-- Result: ' '
Returns a section of the string between to delimiters.
SELECT SPLIT('a/b/c/d', '/', 1);
-- Result: 'a'
SELECT SPLIT('a/b/c/d', '/', -2);
-- Result: 'c'
Returns 1 if character_expression starts with character_prefix; otherwise, 0.
SELECT STARTSWITH('0123456', '012');
-- Result: 1
SELECT STARTSWITH('0123456', '456');
-- Result: 0
Returns the character data converted from the numeric data. For example, STR(123.45, 6, 1) returns 123.5.
SELECT STR('123.456');
-- Result: '123'
SELECT STR('123.456', 2);
-- Result: '**'
SELECT STR('123.456', 10, 2);
-- Result: '123.46'
Inserts a string into another string. It deletes the specified length of characters in the first string at the start position and then inserts the second string into the first string at the start position.
SELECT STUFF('1234567890', 3, 2, 'xx');
-- Result: '12xx567890'
Returns the part of the string with the specified length; starts at the specified index.
SELECT SUBSTRING('1234567890' FROM 3 FOR 2);
-- Result: '34'
SELECT SUBSTRING('1234567890' FROM 3);
-- Result: '34567890'
Converts the value of this instance to its equivalent string representation.
SELECT TOSTRING(123);
-- Result: '123'
SELECT TOSTRING(123.456);
-- Result: '123.456'
SELECT TOSTRING(null);
-- Result: ''
Returns the character expression with leading and/or trailing blanks removed.
SELECT TRIM(' trimmed ');
-- Result: 'trimmed'
SELECT TRIM(LEADING FROM ' trimmed ');
-- Result: 'trimmed '
SELECT TRIM('-' FROM '-----trimmed-----');
-- Result: 'trimmed'
SELECT TRIM(BOTH '-' FROM '-----trimmed-----');
-- Result: 'trimmed'
SELECT TRIM(TRAILING '-' FROM '-----trimmed-----');
-- Result: '-----trimmed'
Returns the integer value defined by the Unicode standard of the first character of the input expression.
Returns the character expression with lowercase character data converted to uppercase.
SELECT UPPER('MIXED case');
-- Result: 'MIXED CASE'
Extracts an XML document using the specified XPath to flatten the XML. A comma is used to separate the outputs by default, but this can be changed by specifying the third parameter.
SELECT XML_EXTRACT('<vowels><ch>a</ch><ch>e</ch><ch>i</ch><ch>o</ch><ch>u</ch></vowels>', '/vowels/ch');
-- Result: 'a,e,i,o,u'
SELECT XML_EXTRACT('<vowels><ch>a</ch><ch>e</ch><ch>i</ch><ch>o</ch><ch>u</ch></vowels>', '/vowels/ch', ';');
-- Result: 'a;e;i;o;u'
Returns the current date value.
SELECT CURRENT_DATE();
-- Result: 2018-02-01
Returns the current time stamp of the database system as a datetime value. This value is equal to GETDATE and SYSDATETIME, and is always in the local timezone.
SELECT CURRENT_TIMESTAMP();
-- Result: 2018-02-01 03:04:05
Returns the datetime value that results from adding the specified number (a signed integer) to the specified date part of the date.
SELECT DATEADD('d', 5, '2018-02-01');
-- Result: 2018-02-06
SELECT DATEADD('hh', 5, '2018-02-01 00:00:00');
-- Result: 2018-02-01 05:00:00
Returns the difference (a signed integer) of the specified time interval between the specified start date and end date.
SELECT DATEDIFF('d', '2018-02-01', '2018-02-10');
-- Result: 9
SELECT DATEDIFF('hh', '2018-02-01 00:00:00', '2018-02-01 12:00:00');
-- Result: 12
Returns the datetime value for the specified year, month, and day.
SELECT DATEFROMPARTS(2018, 2, 1);
-- Result: 2018-02-01
Returns the character string that represents the specified date part of the specified date.
SELECT DATENAME('yy', '2018-02-01');
-- Result: '2018'
SELECT DATENAME('dw', '2018-02-01');
-- Result: 'Thursday'
Returns a character string that represents the specified date part of the specified date.
SELECT DATEPART('yy', '2018-02-01');
-- Result: 2018
SELECT DATEPART('dw', '2018-02-01');
-- Result: 5
Returns the datetime value for the specified date parts.
SELECT DATETIME2FROMPARTS(2018, 2, 1, 1, 2, 3, 456, 3);
-- Result: 2018-02-01 01:02:03.456
Returns the datetime value for the specified date parts.
SELECT DATETIMEFROMPARTS(2018, 2, 1, 1, 2, 3, 456);
-- Result: 2018-02-01 01:02:03.456
Truncates the date to the precision of the given date part. Modeled after the Oracle TRUNC function.
SELECT DATE_TRUNC('05-04-2005', 'YY');
-- Result: '1/1/2005'
SELECT DATE_TRUNC('05-04-2005', 'MM');
-- Result: '5/1/2005'
Truncates the date to the precision of the given date part. Modeled after the PostgreSQL date_trunc function.
SELECT DATE_TRUNC2('year', '2020-02-04');
-- Result: '2020-01-01'
SELECT DATE_TRUNC2('week', '2020-02-04', 'monday');
-- Result: '2020-02-02', which is the previous Monday
Returns the integer that specifies the day component of the specified date.
SELECT DAY('2018-02-01');
-- Result: 1
SELECT DAYOFMONTH('04/15/2000');
-- Result: 15
SELECT DAYOFWEEK('04/15/2000');
-- Result: 7
SELECT DAYOFYEAR('04/15/2000');
-- Result: 106
Returns the last day of the month that contains the specified date with an optional offset.
SELECT EOMONTH('2018-02-01');
-- Result: 2018-02-28
SELECT LAST_DAY('2018-02-01');
-- Result: 2018-02-28
SELECT EOMONTH('2018-02-01', 2);
-- Result: 2018-04-30
SELECT FDWEEK('02-08-2018');
-- Result: 2/4/2018
SELECT FDMONTH('02-08-2018');
-- Result: 2/1/2018
SELECT FDQUARTER('05-08-2018');
-- Result: 4/1/2018
Returns the time stamp associated with the Date Modified of the relevant file.
SELECT FILEMODIFIEDTIME('C:/Documents/myfile.txt');
-- Result: 6/25/2019 10:06:58 AM
Returns a date derived from the number of days after 1582-10-15 (based upon the Gregorian calendar). This will be equivalent to the MYSQL FROM_DAYS function.
SELECT FROM_DAYS(736000); -- Result: 2/6/2015
Returns the current time stamp of the database system as a datetime value. This value is equal to CURRENT_TIMESTAMP and SYSDATETIME, and is always in the local timezone.
SELECT GETDATE();
-- Result: 2018-02-01 03:04:05
Returns the current time stamp of the database system formatted as a UTC datetime value. This value is equal to SYSUTCDATETIME.
SELECT GETUTCDATE();
-- For example, if the local timezone is Eastern European Time (GMT+2)
-- Result: 2018-02-01 05:04:05
Returns the hour component from the provided datetime.
SELECT HOUR('02-02-2020 11:30:00');
-- Result: 11
Returns 1 if the value is a valid date, time, or datetime value; otherwise, 0.
SELECT ISDATE('2018-02-01', 'yyyy-MM-dd');
-- Result: 1
SELECT ISDATE('Not a date');
-- Result: 0
Returns a time stamp equivalent to exactly one week before the current date.
SELECT LAST_WEEK(); //Assume the date is 3/17/2020 -- Result: 3/10/2020
Returns a time stamp equivalent to exactly one month before the current date.
SELECT LAST_MONTH(); //Assume the date is 3/17/2020 -- Result: 2/17/2020
Returns a time stamp equivalent to exactly one year before the current date.
SELECT LAST_YEAR(); //Assume the date is 3/17/2020 -- Result: 3/10/2019
Returns the last day of the provided week.
SELECT LDWEEK('02-02-2020');
-- Result: 2/8/2020
Returns the last day of the provided month.
SELECT LDMONTH('02-02-2020');
-- Result: 2/29/2020
Returns the last day of the provided quarter.
SELECT LDQUARTER('02-02-2020');
-- Result: 3/31/2020
Returns a date value from a year and a number of days.
SELECT MAKEDATE(2020, 1);
-- Result: 2020-01-01
Returns the minute component from the provided datetime.
SELECT MINUTE('02-02-2020 11:15:00');
-- Result: 15
Returns the month component from the provided datetime.
SELECT MONTH('02-02-2020');
-- Result: 2
Returns the quarter associated with the provided datetime.
SELECT QUARTER('02-02-2020');
-- Result: 1
Returns the second component from the provided datetime.
SELECT SECOND('02-02-2020 11:15:23');
-- Result: 23
Returns the datetime value for the specified date and time.
SELECT SMALLDATETIMEFROMPARTS(2018, 2, 1, 1, 2);
-- Result: 2018-02-01 01:02:00
Parses the provided string value and returns the corresponding datetime.
SELECT STRTODATE('03*04*2020','dd*MM*yyyy');
-- Result: 4/3/2020
Returns the current time stamp as a datetime value of the database system. It is equal to GETDATE and CURRENT_TIMESTAMP, and is always in the local timezone.
SELECT SYSDATETIME();
-- Result: 2018-02-01 03:04:05
Returns the current system date and time as a UTC datetime value. It is equal to GETUTCDATE.
SELECT SYSUTCDATETIME();
-- For example, if the local timezone is Eastern European Time (GMT+2)
-- Result: 2018-02-01 05:04:05
Returns the time value for the specified time and with the specified precision.
SELECT TIMEFROMPARTS(1, 2, 3, 456, 3);
-- Result: 01:02:03.456
Returns the number of days since 0000-00-01. This will only return a value for dates on or after 1582-10-15 (based upon the Gregorian calendar). This will be equivalent to the MYSQL TO_DAYS function.
SELECT TO_DAYS('02-06-2015');
-- Result: 736000
Returns the week (of the year) associated with the provided datetime.
SELECT WEEK('02-17-2020 11:15:23');
-- Result: 8
Returns the integer that specifies the year of the specified date.
SELECT YEAR('2018-02-01');
-- Result: 2018
Returns the absolute (positive) value of the specified numeric expression.
SELECT ABS(15);
-- Result: 15
SELECT ABS(-15);
-- Result: 15
Returns the arc cosine, the angle in radians whose cosine is the specified float expression.
SELECT ACOS(0.5);
-- Result: 1.0471975511966
Returns the arc sine, the angle in radians whose sine is the specified float expression.
SELECT ASIN(0.5);
-- Result: 0.523598775598299
Returns the arc tangent, the angle in radians whose tangent is the specified float expression.
SELECT ATAN(10);
-- Result: 1.47112767430373
Returns the angle in radians between the positive x-axis and the ray from the origin to the point (y, x) where x and y are the values of the two specified float expressions.
SELECT ATN2(1, 1);
-- Result: 0.785398163397448
Returns the smallest integer greater than or equal to the specified numeric expression.
SELECT CEILING(1.3);
-- Result: 2
SELECT CEILING(1.5);
-- Result: 2
SELECT CEILING(1.7);
-- Result: 2
Returns the trigonometric cosine of the specified angle in radians in the specified expression.
SELECT COS(1);
-- Result: 0.54030230586814
Returns the trigonometric cotangent of the angle in radians specified by float_expression.
SELECT COT(1);
-- Result: 0.642092615934331
Returns the angle in degrees for the angle specified in radians.
SELECT DEGREES(3.1415926);
-- Result: 179.999996929531
Returns the exponential value of the specified float expression. For example, EXP(LOG(20)) is 20.
SELECT EXP(2);
-- Result: 7.38905609893065
Evaluates the expression.
SELECT EXPR('1 + 2 * 3');
-- Result: 7
SELECT EXPR('1 + 2 * 3 == 7');
-- Result: true
Returns the largest integer less than or equal to the numeric expression.
SELECT FLOOR(1.3);
-- Result: 1
SELECT FLOOR(1.5);
-- Result: 1
SELECT FLOOR(1.7);
-- Result: 1
Returns the greatest of the supplied integers.
SELECT GREATEST(3,5,8,10,1) -- Result: 10
Returns a the equivalent hex for the input value.
SELECT HEX(866849198);
-- Result: 33AB11AE
SELECT HEX('Sample Text');
-- Result: 53616D706C652054657874
Returns the least of the supplied integers.
SELECT LEAST(3,5,8,10,1) -- Result: 1
Returns the natural logarithm of the specified float expression.
SELECT LOG(7.3890560);
-- Result: 1.99999998661119
Returns the base-10 logarithm of the specified float expression.
SELECT LOG10(10000);
-- Result: 4
Returns the integer value associated with the remainder when dividing the dividend by the divisor.
SELECT MOD(10,3); -- Result: 1
Returns the opposite to the real number input.
SELECT NEGATE(10); -- Result: -10 SELECT NEGATE(-12.4) --Result: 12.4
Returns the constant value of pi.
SELECT PI()
-- Result: 3.14159265358979
Returns the value of the specified expression raised to the specified power.
SELECT POWER(2, 10);
-- Result: 1024
SELECT POWER(2, -2);
-- Result: 0.25
Returns the angle in radians of the angle in degrees.
SELECT RADIANS(180);
-- Result: 3.14159265358979
Returns a pseudorandom float value from 0 through 1, exclusive.
SELECT RAND();
-- This result may be different, since the seed is randomized
-- Result: 0.873159630165044
SELECT RAND(1);
-- This result will always be the same, since the seed is constant
-- Result: 0.248668584157093
Returns the numeric value rounded to the specified length or precision.
SELECT ROUND(1.3, 0);
-- Result: 1
SELECT ROUND(1.55, 1);
-- Result: 1.6
SELECT ROUND(1.7, 0, 0);
-- Result: 2
SELECT ROUND(1.7, 0, 1);
-- Result: 1
SELECT ROUND (1.24);
-- Result: 1.0
Returns the positive sign (1), 0, or negative sign (-1) of the specified expression.
SELECT SIGN(0);
-- Result: 0
SELECT SIGN(10);
-- Result: 1
SELECT SIGN(-10);
-- Result: -1
Returns the trigonometric sine of the angle in radians.
SELECT SIN(1);
-- Result: 0.841470984807897
Returns the square root of the specified float value.
SELECT SQRT(100);
-- Result: 10
Returns the square of the specified float value.
SELECT SQUARE(10);
-- Result: 100
SELECT SQUARE(-10);
-- Result: 100
Returns the tangent of the input expression.
SELECT TAN(1);
-- Result: 1.5574077246549
Returns the supplied decimal number truncated to have the supplied decimal precision.
SELECT TRUNC(10.3423,2); -- Result: 10.34
To create new records, use INSERT statements.
The INSERT statement specifies the columns to be inserted and the new column values. You can specify the column values in a comma-separated list in the VALUES clause, as shown in the following example:
INSERT INTO <table_name>
( <column_reference> [ , ... ] )
VALUES
( { <expression> | NULL } [ , ... ] )
<expression> ::=
| @ <parameter>
| ?
| <literal>
The following is an example query:
INSERT INTO [CData].[Default].Customers (CompanyName) VALUES ('RSSBus Inc.')
To execute stored procedures, you can use EXECUTE or EXEC statements.
EXEC and EXECUTE assign stored procedure inputs, referenced by name, to values or parameter names.
To execute a stored procedure as an SQL statement, use the following syntax:
{ EXECUTE | EXEC } <stored_proc_name>
{
[ @ ] <input_name> = <expression>
} [ , ... ]
<expression> ::=
| @ <parameter>
| ?
| <literal>
Reference stored procedure inputs by name:
EXECUTE my_proc @second = 2, @first = 1, @third = 3;
Execute a parameterized stored procedure statement:
EXECUTE my_proc second = @p1, first = @p2, third = @p3;
PIVOT and UNPIVOT can be used to change a table-valued expression into another table.
"SELECT 'AverageCost' AS Cost_Sorted_By_Production_Days, [0], [1], [2], [3], [4]
FROM
(
SELECT DaysToManufacture, StandardCost
FROM Production.Product
) AS SourceTable
PIVOT
(
AVG(StandardCost)
FOR DaysToManufacture IN ([0], [1], [2], [3], [4])
) AS PivotTable;"
"SELECT VendorID, Employee, Orders
FROM
(SELECT VendorID, Emp1, Emp2, Emp3, Emp4, Emp5
FROM pvt) p
UNPIVOT
(Orders FOR Employee IN
(Emp1, Emp2, Emp3, Emp4, Emp5)
)AS unpvt;"
For further information on PIVOT and UNPIVOT, see FROM clause plus JOIN, APPLY, PIVOT (Transact-SQL)
The Cloud models Apache Impala instances as relational databases. The Cloud leverages the Impala Server Thrift API, to enable bidirectional access to Apache Impala data through SQL. Impala Server 2.2.0 and above are supported.
You can query the system tables described in this section to access schema information, information on data source functionality, and batch operation statistics.
The following tables return database metadata for Apache Impala:
The following tables return information about how to connect to and query the data source:
The following table returns query statistics for data modification queries, including batch operations::
Lists the available databases.
The following query retrieves all databases determined by the connection string:
SELECT * FROM sys_catalogs
| Name | Type | Description |
| CatalogName | String | The database name. |
Lists the available schemas.
The following query retrieves all available schemas:
SELECT * FROM sys_schemas
| Name | Type | Description |
| CatalogName | String | The database name. |
| SchemaName | String | The schema name. |
Lists the available tables.
The following query retrieves the available tables and views:
SELECT * FROM sys_tables
| Name | Type | Description |
| CatalogName | String | The database containing the table or view. |
| SchemaName | String | The schema containing the table or view. |
| TableName | String | The name of the table or view. |
| TableType | String | The table type (table or view). |
| Description | String | A description of the table or view. |
| IsUpdateable | Boolean | Whether the table can be updated. |
Describes the columns of the available tables and views.
The following query returns the columns and data types for the [CData].[Default].Customers table:
SELECT ColumnName, DataTypeName FROM sys_tablecolumns WHERE TableName='Customers' AND CatalogName='CData' AND SchemaName='Default'
| Name | Type | Description |
| CatalogName | String | The name of the database containing the table or view. |
| SchemaName | String | The schema containing the table or view. |
| TableName | String | The name of the table or view containing the column. |
| ColumnName | String | The column name. |
| DataTypeName | String | The data type name. |
| DataType | Int32 | An integer indicating the data type. This value is determined at run time based on the environment. |
| Length | Int32 | The storage size of the column. |
| DisplaySize | Int32 | The designated column's normal maximum width in characters. |
| NumericPrecision | Int32 | The maximum number of digits in numeric data. The column length in characters for character and date-time data. |
| NumericScale | Int32 | The column scale or number of digits to the right of the decimal point. |
| IsNullable | Boolean | Whether the column can contain null. |
| Description | String | A brief description of the column. |
| Ordinal | Int32 | The sequence number of the column. |
| IsAutoIncrement | String | Whether the column value is assigned in fixed increments. |
| IsGeneratedColumn | String | Whether the column is generated. |
| IsHidden | Boolean | Whether the column is hidden. |
| IsArray | Boolean | Whether the column is an array. |
Lists the available stored procedures.
The following query retrieves the available stored procedures:
SELECT * FROM sys_procedures
| Name | Type | Description |
| CatalogName | String | The database containing the stored procedure. |
| SchemaName | String | The schema containing the stored procedure. |
| ProcedureName | String | The name of the stored procedure. |
| Description | String | A description of the stored procedure. |
| ProcedureType | String | The type of the procedure, such as PROCEDURE or FUNCTION. |
Describes stored procedure parameters.
The following query returns information about all of the input parameters for the SearchSuppliers stored procedure:
SELECT * FROM sys_procedureparameters WHERE ProcedureName='SearchSuppliers' AND Direction=1 OR Direction=2
| Name | Type | Description |
| CatalogName | String | The name of the database containing the stored procedure. |
| SchemaName | String | The name of the schema containing the stored procedure. |
| ProcedureName | String | The name of the stored procedure containing the parameter. |
| ColumnName | String | The name of the stored procedure parameter. |
| Direction | Int32 | An integer corresponding to the type of the parameter: input (1), input/output (2), or output(4). input/output type parameters can be both input and output parameters. |
| DataTypeName | String | The name of the data type. |
| DataType | Int32 | An integer indicating the data type. This value is determined at run time based on the environment. |
| Length | Int32 | The number of characters allowed for character data. The number of digits allowed for numeric data. |
| NumericPrecision | Int32 | The maximum precision for numeric data. The column length in characters for character and date-time data. |
| NumericScale | Int32 | The number of digits to the right of the decimal point in numeric data. |
| IsNullable | Boolean | Whether the parameter can contain null. |
| IsRequired | Boolean | Whether the parameter is required for execution of the procedure. |
| IsArray | Boolean | Whether the parameter is an array. |
| Description | String | The description of the parameter. |
| Ordinal | Int32 | The index of the parameter. |
Describes the primary and foreign keys.
The following query retrieves the primary key for the [CData].[Default].Customers table:
SELECT * FROM sys_keycolumns WHERE IsKey='True' AND TableName='Customers' AND CatalogName='CData' AND SchemaName='Default'
| Name | Type | Description |
| CatalogName | String | The name of the database containing the key. |
| SchemaName | String | The name of the schema containing the key. |
| TableName | String | The name of the table containing the key. |
| ColumnName | String | The name of the key column. |
| IsKey | Boolean | Whether the column is a primary key in the table referenced in the TableName field. |
| IsForeignKey | Boolean | Whether the column is a foreign key referenced in the TableName field. |
| PrimaryKeyName | String | The name of the primary key. |
| ForeignKeyName | String | The name of the foreign key. |
| ReferencedCatalogName | String | The database containing the primary key. |
| ReferencedSchemaName | String | The schema containing the primary key. |
| ReferencedTableName | String | The table containing the primary key. |
| ReferencedColumnName | String | The column name of the primary key. |
Describes the foreign keys.
The following query retrieves all foreign keys which refer to other tables:
SELECT * FROM sys_foreignkeys WHERE ForeignKeyType = 'FOREIGNKEY_TYPE_IMPORT'
| Name | Type | Description |
| CatalogName | String | The name of the database containing the key. |
| SchemaName | String | The name of the schema containing the key. |
| TableName | String | The name of the table containing the key. |
| ColumnName | String | The name of the key column. |
| PrimaryKeyName | String | The name of the primary key. |
| ForeignKeyName | String | The name of the foreign key. |
| ReferencedCatalogName | String | The database containing the primary key. |
| ReferencedSchemaName | String | The schema containing the primary key. |
| ReferencedTableName | String | The table containing the primary key. |
| ReferencedColumnName | String | The column name of the primary key. |
| ForeignKeyType | String | Designates whether the foreign key is an import (points to other tables) or export (referenced from other tables) key. |
Describes the primary keys.
The following query retrieves the primary keys from all tables and views:
SELECT * FROM sys_primarykeys
| Name | Type | Description |
| CatalogName | String | The name of the database containing the key. |
| SchemaName | String | The name of the schema containing the key. |
| TableName | String | The name of the table containing the key. |
| ColumnName | String | The name of the key column. |
| KeySeq | String | The sequence number of the primary key. |
| KeyName | String | The name of the primary key. |
Describes the available indexes. By filtering on indexes, you can write more selective queries with faster query response times.
The following query retrieves all indexes that are not primary keys:
SELECT * FROM sys_indexes WHERE IsPrimary='false'
| Name | Type | Description |
| CatalogName | String | The name of the database containing the index. |
| SchemaName | String | The name of the schema containing the index. |
| TableName | String | The name of the table containing the index. |
| IndexName | String | The index name. |
| ColumnName | String | The name of the column associated with the index. |
| IsUnique | Boolean | True if the index is unique. False otherwise. |
| IsPrimary | Boolean | True if the index is a primary key. False otherwise. |
| Type | Int16 | An integer value corresponding to the index type: statistic (0), clustered (1), hashed (2), or other (3). |
| SortOrder | String | The sort order: A for ascending or D for descending. |
| OrdinalPosition | Int16 | The sequence number of the column in the index. |
Returns information on the available connection properties and those set in the connection string.
When querying this table, the config connection string should be used:
jdbc:cdata:apacheimpala:config:
This connection string enables you to query this table without a valid connection.
The following query retrieves all connection properties that have been set in the connection string or set through a default value:
SELECT * FROM sys_connection_props WHERE Value <> ''
| Name | Type | Description |
| Name | String | The name of the connection property. |
| ShortDescription | String | A brief description. |
| Type | String | The data type of the connection property. |
| Default | String | The default value if one is not explicitly set. |
| Values | String | A comma-separated list of possible values. A validation error is thrown if another value is specified. |
| Value | String | The value you set or a preconfigured default. |
| Required | Boolean | Whether the property is required to connect. |
| Category | String | The category of the connection property. |
| IsSessionProperty | String | Whether the property is a session property, used to save information about the current connection. |
| Sensitivity | String | The sensitivity level of the property. This informs whether the property is obfuscated in logging and authentication forms. |
| PropertyName | String | A camel-cased truncated form of the connection property name. |
| Ordinal | Int32 | The index of the parameter. |
| CatOrdinal | Int32 | The index of the parameter category. |
| Hierarchy | String | Shows dependent properties associated that need to be set alongside this one. |
| Visible | Boolean | Informs whether the property is visible in the connection UI. |
| ETC | String | Various miscellaneous information about the property. |
Describes the SELECT query processing that the Cloud can offload to the data source.
See SQL Compliance for SQL syntax details.
Below is an example data set of SQL capabilities. The following result set indicates the SELECT functionality that the Cloud can offload to the data source or process client side. Your data source may support additional SQL syntax. Some aspects of SELECT functionality are returned in a comma-separated list if supported; otherwise, the column contains NO.
| Name | Description | Possible Values |
| AGGREGATE_FUNCTIONS | Supported aggregation functions. | AVG, COUNT, MAX, MIN, SUM, DISTINCT |
| COUNT | Whether COUNT function is supported. | YES, NO |
| IDENTIFIER_QUOTE_OPEN_CHAR | The opening character used to escape an identifier. | [ |
| IDENTIFIER_QUOTE_CLOSE_CHAR | The closing character used to escape an identifier. | ] |
| SUPPORTED_OPERATORS | A list of supported SQL operators. | =, >, <, >=, <=, <>, !=, LIKE, NOT LIKE, IN, NOT IN, IS NULL, IS NOT NULL, AND, OR |
| GROUP_BY | Whether GROUP BY is supported, and, if so, the degree of support. | NO, NO_RELATION, EQUALS_SELECT, SQL_GB_COLLATE |
| OJ_CAPABILITIES | The supported varieties of outer joins supported. | NO, LEFT, RIGHT, FULL, INNER, NOT_ORDERED, ALL_COMPARISON_OPS |
| OUTER_JOINS | Whether outer joins are supported. | YES, NO |
| SUBQUERIES | Whether subqueries are supported, and, if so, the degree of support. | NO, COMPARISON, EXISTS, IN, CORRELATED_SUBQUERIES, QUANTIFIED |
| STRING_FUNCTIONS | Supported string functions. | LENGTH, CHAR, LOCATE, REPLACE, SUBSTRING, RTRIM, LTRIM, RIGHT, LEFT, UCASE, SPACE, SOUNDEX, LCASE, CONCAT, ASCII, REPEAT, OCTET, BIT, POSITION, INSERT, TRIM, UPPER, REGEXP, LOWER, DIFFERENCE, CHARACTER, SUBSTR, STR, REVERSE, PLAN, UUIDTOSTR, TRANSLATE, TRAILING, TO, STUFF, STRTOUUID, STRING, SPLIT, SORTKEY, SIMILAR, REPLICATE, PATINDEX, LPAD, LEN, LEADING, KEY, INSTR, INSERTSTR, HTML, GRAPHICAL, CONVERT, COLLATION, CHARINDEX, BYTE |
| NUMERIC_FUNCTIONS | Supported numeric functions. | ABS, ACOS, ASIN, ATAN, ATAN2, CEILING, COS, COT, EXP, FLOOR, LOG, MOD, SIGN, SIN, SQRT, TAN, PI, RAND, DEGREES, LOG10, POWER, RADIANS, ROUND, TRUNCATE |
| TIMEDATE_FUNCTIONS | Supported date/time functions. | NOW, CURDATE, DAYOFMONTH, DAYOFWEEK, DAYOFYEAR, MONTH, QUARTER, WEEK, YEAR, CURTIME, HOUR, MINUTE, SECOND, TIMESTAMPADD, TIMESTAMPDIFF, DAYNAME, MONTHNAME, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, EXTRACT |
| REPLICATION_SKIP_TABLES | Indicates tables skipped during replication. | |
| REPLICATION_TIMECHECK_COLUMNS | A string array containing a list of columns which will be used to check for (in the given order) to use as a modified column during replication. | |
| IDENTIFIER_PATTERN | String value indicating what string is valid for an identifier. | |
| SUPPORT_TRANSACTION | Indicates if the provider supports transactions such as commit and rollback. | YES, NO |
| DIALECT | Indicates the SQL dialect to use. | |
| KEY_PROPERTIES | Indicates the properties which identify the uniform database. | |
| SUPPORTS_MULTIPLE_SCHEMAS | Indicates if multiple schemas may exist for the provider. | YES, NO |
| SUPPORTS_MULTIPLE_CATALOGS | Indicates if multiple catalogs may exist for the provider. | YES, NO |
| DATASYNCVERSION | The CData Data Sync version needed to access this driver. | Standard, Starter, Professional, Enterprise |
| DATASYNCCATEGORY | The CData Data Sync category of this driver. | Source, Destination, Cloud Destination |
| SUPPORTSENHANCEDSQL | Whether enhanced SQL functionality beyond what is offered by the API is supported. | TRUE, FALSE |
| SUPPORTS_BATCH_OPERATIONS | Whether batch operations are supported. | YES, NO |
| SQL_CAP | All supported SQL capabilities for this driver. | SELECT, INSERT, DELETE, UPDATE, TRANSACTIONS, ORDERBY, OAUTH, ASSIGNEDID, LIMIT, LIKE, BULKINSERT, COUNT, BULKDELETE, BULKUPDATE, GROUPBY, HAVING, AGGS, OFFSET, REPLICATE, COUNTDISTINCT, JOINS, DROP, CREATE, DISTINCT, INNERJOINS, SUBQUERIES, ALTER, MULTIPLESCHEMAS, GROUPBYNORELATION, OUTERJOINS, UNIONALL, UNION, UPSERT, GETDELETED, CROSSJOINS, GROUPBYCOLLATE, MULTIPLECATS, FULLOUTERJOIN, MERGE, JSONEXTRACT, BULKUPSERT, SUM, SUBQUERIESFULL, MIN, MAX, JOINSFULL, XMLEXTRACT, AVG, MULTISTATEMENTS, FOREIGNKEYS, CASE, LEFTJOINS, COMMAJOINS, WITH, LITERALS, RENAME, NESTEDTABLES, EXECUTE, BATCH, BASIC, INDEX |
| PREFERRED_CACHE_OPTIONS | A string value specifies the preferred cacheOptions. | |
| ENABLE_EF_ADVANCED_QUERY | Indicates if the driver directly supports advanced queries coming from Entity Framework. If not, queries will be handled client side. | YES, NO |
| PSEUDO_COLUMNS | A string array indicating the available pseudo columns. | |
| MERGE_ALWAYS | If the value is true, The Merge Mode is forcibly executed in Data Sync. | TRUE, FALSE |
| REPLICATION_MIN_DATE_QUERY | A select query to return the replicate start datetime. | |
| REPLICATION_MIN_FUNCTION | Allows a provider to specify the formula name to use for executing a server side min. | |
| REPLICATION_START_DATE | Allows a provider to specify a replicate startdate. | |
| REPLICATION_MAX_DATE_QUERY | A select query to return the replicate end datetime. | |
| REPLICATION_MAX_FUNCTION | Allows a provider to specify the formula name to use for executing a server side max. | |
| IGNORE_INTERVALS_ON_INITIAL_REPLICATE | A list of tables which will skip dividing the replicate into chunks on the initial replicate. | |
| CHECKCACHE_USE_PARENTID | Indicates whether the CheckCache statement should be done against the parent key column. | TRUE, FALSE |
| CREATE_SCHEMA_PROCEDURES | Indicates stored procedures that can be used for generating schema files. |
The following query retrieves the operators that can be used in the WHERE clause:
SELECT * FROM sys_sqlinfo WHERE Name='SUPPORTED_OPERATORS'
Note that individual tables may have different limitations or requirements on the WHERE clause; refer to the Data Model section for more information.
| Name | Type | Description |
| NAME | String | A component of SQL syntax, or a capability that can be processed on the server. |
| VALUE | String | Detail on the supported SQL or SQL syntax. |
Returns information about attempted modifications.
The following query retrieves the Ids of the modified rows in a batch operation:
SELECT * FROM sys_identity
| Name | Type | Description |
| Id | String | The database-generated Id returned from a data modification operation. |
| Batch | String | An identifier for the batch. 1 for a single operation. |
| Operation | String | The result of the operation in the batch: INSERTED, UPDATED, or DELETED. |
| Message | String | SUCCESS or an error message if the update in the batch failed. |
The connection string properties are the various options that can be used to establish a connection. This section provides a complete list of the options you can configure in the connection string for this provider. Click the links for further details.
| Property | Description |
| AuthScheme | The authentication scheme used. Accepted values are NoSasl, LDAP and Kerberos. |
| Server | The name of the server running SQL Server. |
| Port | The port for the connection to the Impala Server instance. |
| User | The username used to authenticate with Impala. |
| Password | The password used to authenticate with Impala. |
| ProtocolVersion | The Thrift protocol version to use when connecting to the Impala server. |
| Database | The name of the Impala database to use by default. |
| TransportMode | The transport mode to use to communicate with the Impala server. Accepted entries are BINARY and HTTP. |
| Property | Description |
| KerberosKDC | The Kerberos Key Distribution Center (KDC) service used to authenticate the user. |
| KerberosRealm | The Kerberos Realm used to authenticate the user. |
| KerberosSPN | The service principal name (SPN) for the Kerberos Domain Controller. |
| KerberosKeytabFile | The Keytab file containing your pairs of Kerberos principals and encrypted keys. |
| KerberosServiceRealm | The Kerberos realm of the service. |
| KerberosServiceKDC | The Kerberos KDC of the service. |
| KerberosTicketCache | The full file path to an MIT Kerberos credential cache file. |
| Property | Description |
| SSLClientCert | The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). |
| SSLClientCertType | The type of key store containing the TLS/SSL client certificate. |
| SSLClientCertPassword | The password for the TLS/SSL client certificate. |
| SSLClientCertSubject | The subject of the TLS/SSL client certificate. |
| SSLServerCert | The certificate to be accepted from the server when connecting using TLS/SSL. |
| Property | Description |
| FirewallType | The protocol used by a proxy-based firewall. |
| FirewallServer | The name or IP address of a proxy-based firewall. |
| FirewallPort | The TCP port for a proxy-based firewall. |
| FirewallUser | The user name to use to authenticate with a proxy-based firewall. |
| FirewallPassword | A password used to authenticate to a proxy-based firewall. |
| Property | Description |
| ProxyAutoDetect | This indicates whether to use the system proxy settings or not. This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings. |
| ProxyServer | The hostname or IP address of a proxy to route HTTP traffic through. |
| ProxyPort | The TCP port the ProxyServer proxy is running on. |
| ProxyAuthScheme | The authentication type to use to authenticate to the ProxyServer proxy. |
| ProxyUser | A user name to be used to authenticate to the ProxyServer proxy. |
| ProxyPassword | A password to be used to authenticate to the ProxyServer proxy. |
| ProxySSLType | The SSL type to use when connecting to the ProxyServer proxy. |
| ProxyExceptions | A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the ProxyServer . |
| Property | Description |
| Logfile | A filepath which designates the name and location of the log file. |
| Verbosity | The verbosity level that determines the amount of detail included in the log file. |
| LogModules | Core modules to be included in the log file. |
| MaxLogFileSize | A string specifying the maximum size in bytes for a log file (for example, 10 MB). |
| MaxLogFileCount | A string specifying the maximum file count of log files. |
| Property | Description |
| Location | A path to the directory that contains the schema files defining tables, views, and stored procedures. |
| BrowsableSchemas | This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC. |
| Tables | This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC. |
| Views | Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC. |
| Property | Description |
| AutoCache | Automatically caches the results of SELECT queries into a cache database specified by either CacheLocation or both of CacheConnection and CacheProvider . |
| CacheLocation | Specifies the path to the cache when caching to a file. |
| CacheTolerance | The tolerance for stale data in the cache specified in seconds when using AutoCache . |
| Offline | Use offline mode to get the data from the cache instead of the live source. |
| CacheMetadata | This property determines whether or not to cache the table metadata to a file store. |
| Property | Description |
| HTTPPath | The path component of the URL endpoint when using HTTP TransportMode. |
| MaxRows | Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time. |
| Other | These hidden properties are used only in specific use cases. |
| Pagesize | The maximum number of results to return per page from Apache Impala. |
| PseudoColumns | This property indicates whether or not to include pseudo columns as columns to the table. |
| QueryPassthrough | This option passes the query to the Apache Impala server as is. |
| Readonly | You can use this property to enforce read-only access to Apache Impala from the provider. |
| RTK | The runtime key used for licensing. |
| Timeout | The value in seconds until the timeout error is thrown, canceling the operation. |
| UserDefinedViews | A filepath pointing to the JSON configuration file containing your custom views. |
| UseSSL | Specifies whether to use SSL Encryption when connecting to Impala. |
This section provides a complete list of the Authentication properties you can configure in the connection string for this provider.
| Property | Description |
| AuthScheme | The authentication scheme used. Accepted values are NoSasl, LDAP and Kerberos. |
| Server | The name of the server running SQL Server. |
| Port | The port for the connection to the Impala Server instance. |
| User | The username used to authenticate with Impala. |
| Password | The password used to authenticate with Impala. |
| ProtocolVersion | The Thrift protocol version to use when connecting to the Impala server. |
| Database | The name of the Impala database to use by default. |
| TransportMode | The transport mode to use to communicate with the Impala server. Accepted entries are BINARY and HTTP. |
The authentication scheme used. Accepted values are NoSasl, LDAP and Kerberos.
string
"NoSasl"
The AuthScheme used to authenticate with Impala.
| NoSasl (default) | default |
| LDAP | Used when the enable_ldap_auth property is set to true and ldap_uri property is not empty. |
| Kerberos | Used when the keytab_file property is is not empty. |
The name of the server running SQL Server.
string
""
Set this property to the name or network address of the SQL Server instance.
The port for the connection to the Impala Server instance.
string
"21050"
When using BINARY TransportMode, this property should be set to the value in the 'hs2_port'(default 21050) property of the impala configuration (http://host:25000/varz).
When using HTTP TransportMode, this property should be set to the value in the 'hs2_http_port'(default 28000) property of the impala configuration (http://host:25000/varz).
The username used to authenticate with Impala.
string
""
The username used to authenticate with Impala.
The password used to authenticate with Impala.
string
""
The password used to authenticate with Impala.
The Thrift protocol version to use when connecting to the Impala server.
string
"7"
The most efficient protocol version will be determined automatically by the CData Cloud upon connecting to Impala. This property allows you to explicitly specify the version to use and overrides the version determined by the CData Cloud.
The name of the Impala database to use by default.
string
""
When specified, the CData Cloud will issue a 'USE [Database]' command upon connecting to Impala. This will be the database schema used when executing queries that do not have a schema explicitly specified.
To execute queries on other schemas, the schema can be explicitly specified in the statement.
When Database is not set, the 'default' database schema will be used (no 'USE' statement is issued to Impala in this case).
The transport mode to use to communicate with the Impala server. Accepted entries are BINARY and HTTP.
string
"BINARY"
The transport mode used to communicate with the Impala server.
This section provides a complete list of the Kerberos properties you can configure in the connection string for this provider.
| Property | Description |
| KerberosKDC | The Kerberos Key Distribution Center (KDC) service used to authenticate the user. |
| KerberosRealm | The Kerberos Realm used to authenticate the user. |
| KerberosSPN | The service principal name (SPN) for the Kerberos Domain Controller. |
| KerberosKeytabFile | The Keytab file containing your pairs of Kerberos principals and encrypted keys. |
| KerberosServiceRealm | The Kerberos realm of the service. |
| KerberosServiceKDC | The Kerberos KDC of the service. |
| KerberosTicketCache | The full file path to an MIT Kerberos credential cache file. |
The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
string
""
The Kerberos properties are used when using SPNEGO or Windows Authentication. The Cloud will request session tickets and temporary session keys from the Kerberos KDC service. The Kerberos KDC service is conventionally colocated with the domain controller.
If Kerberos KDC is not specified, the Cloud will attempt to detect these properties automatically from the following locations:
The Kerberos Realm used to authenticate the user.
string
""
The Kerberos properties are used when using SPNEGO or Windows Authentication. The Kerberos Realm is used to authenticate the user with the Kerberos Key Distribution Service (KDC). The Kerberos Realm can be configured by an administrator to be any string, but conventionally it is based on the domain name.
If Kerberos Realm is not specified, the Cloud will attempt to detect these properties automatically from the following locations:
The service principal name (SPN) for the Kerberos Domain Controller.
string
""
If the SPN on the Kerberos Domain Controller is not the same as the URL that you are authenticating to, use this property to set the SPN.
The Keytab file containing your pairs of Kerberos principals and encrypted keys.
string
""
The Keytab file containing your pairs of Kerberos principals and encrypted keys.
The Kerberos realm of the service.
string
""
The KerberosServiceRealm is the specify the service Kerberos realm when using cross-realm Kerberos authentication.
In most cases, a single realm and KDC machine are used to perform the Kerberos authentication and this property is not required.
This property is available for complex setups where a different realm and KDC machine are used to obtain an authentication ticket (AS request) and a service ticket (TGS request).
The Kerberos KDC of the service.
string
""
The KerberosServiceKDC is used to specify the service Kerberos KDC when using cross-realm Kerberos authentication.
In most cases, a single realm and KDC machine are used to perform the Kerberos authentication and this property is not required.
This property is available for complex setups where a different realm and KDC machine are used to obtain an authentication ticket (AS request) and a service ticket (TGS request).
The full file path to an MIT Kerberos credential cache file.
string
""
This property can be set if you wish to use a credential cache file that was created using the MIT Kerberos Ticket Manager or kinit command.
This section provides a complete list of the SSL properties you can configure in the connection string for this provider.
| Property | Description |
| SSLClientCert | The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). |
| SSLClientCertType | The type of key store containing the TLS/SSL client certificate. |
| SSLClientCertPassword | The password for the TLS/SSL client certificate. |
| SSLClientCertSubject | The subject of the TLS/SSL client certificate. |
| SSLServerCert | The certificate to be accepted from the server when connecting using TLS/SSL. |
The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL).
string
""
The name of the certificate store for the client certificate.
The SSLClientCertType field specifies the type of the certificate store specified by SSLClientCert. If the store is password protected, specify the password in SSLClientCertPassword.
SSLClientCert is used in conjunction with the SSLClientCertSubject field in order to specify client certificates. If SSLClientCert has a value, and SSLClientCertSubject is set, a search for a certificate is initiated. See SSLClientCertSubject for more information.
Designations of certificate stores are platform-dependent.
The following are designations of the most common User and Machine certificate stores in Windows:
| MY | A certificate store holding personal certificates with their associated private keys. |
| CA | Certifying authority certificates. |
| ROOT | Root certificates. |
| SPC | Software publisher certificates. |
In Java, the certificate store normally is a file containing certificates and optional private keys.
When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (for example, PKCS12 certificate store).
The type of key store containing the TLS/SSL client certificate.
string
"USER"
This property can take one of the following values:
| USER - default | For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note that this store type is not available in Java. |
| MACHINE | For Windows, this specifies that the certificate store is a machine store. Note that this store type is not available in Java. |
| PFXFILE | The certificate store is the name of a PFX (PKCS12) file containing certificates. |
| PFXBLOB | The certificate store is a string (base-64-encoded) representing a certificate store in PFX (PKCS12) format. |
| JKSFILE | The certificate store is the name of a Java key store (JKS) file containing certificates. Note that this store type is only available in Java. |
| JKSBLOB | The certificate store is a string (base-64-encoded) representing a certificate store in JKS format. Note that this store type is only available in Java. |
| PEMKEY_FILE | The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate. |
| PEMKEY_BLOB | The certificate store is a string (base64-encoded) that contains a private key and an optional certificate. |
| PUBLIC_KEY_FILE | The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate. |
| PUBLIC_KEY_BLOB | The certificate store is a string (base-64-encoded) that contains a PEM- or DER-encoded public key certificate. |
| SSHPUBLIC_KEY_FILE | The certificate store is the name of a file that contains an SSH-style public key. |
| SSHPUBLIC_KEY_BLOB | The certificate store is a string (base-64-encoded) that contains an SSH-style public key. |
| P7BFILE | The certificate store is the name of a PKCS7 file containing certificates. |
| PPKFILE | The certificate store is the name of a file that contains a PuTTY Private Key (PPK). |
| XMLFILE | The certificate store is the name of a file that contains a certificate in XML format. |
| XMLBLOB | The certificate store is a string that contains a certificate in XML format. |
The password for the TLS/SSL client certificate.
string
""
If the certificate store is of a type that requires a password, this property is used to specify that password to open the certificate store.
The subject of the TLS/SSL client certificate.
string
"*"
When loading a certificate the subject is used to locate the certificate in the store.
If an exact match is not found, the store is searched for subjects containing the value of the property. If a match is still not found, the property is set to an empty string, and no certificate is selected.
The special value "*" picks the first certificate in the certificate store.
The certificate subject is a comma separated list of distinguished name fields and values. For example, "CN=www.server.com, OU=test, C=US, [email protected]". The common fields and their meanings are shown below.
| Field | Meaning |
| CN | Common Name. This is commonly a host name like www.server.com. |
| O | Organization |
| OU | Organizational Unit |
| L | Locality |
| S | State |
| C | Country |
| E | Email Address |
If a field value contains a comma, it must be quoted.
The certificate to be accepted from the server when connecting using TLS/SSL.
string
""
If using a TLS/SSL connection, this property can be used to specify the TLS/SSL certificate to be accepted from the server. Any other certificate that is not trusted by the machine is rejected.
This property can take the following forms:
| Description | Example |
| A full PEM Certificate (example shortened for brevity) | -----BEGIN CERTIFICATE----- MIIChTCCAe4CAQAwDQYJKoZIhv......Qw== -----END CERTIFICATE----- |
| A path to a local file containing the certificate | C:\cert.cer |
| The public key (example shortened for brevity) | -----BEGIN RSA PUBLIC KEY----- MIGfMA0GCSq......AQAB -----END RSA PUBLIC KEY----- |
| The MD5 Thumbprint (hex values can also be either space or colon separated) | ecadbdda5a1529c58a1e9e09828d70e4 |
| The SHA1 Thumbprint (hex values can also be either space or colon separated) | 34a929226ae0819f2ec14b4a3d904f801cbb150d |
If not specified, any certificate trusted by the machine is accepted.
Use '*' to signify to accept all certificates. Note that this is not recommended due to security concerns.
This section provides a complete list of the Firewall properties you can configure in the connection string for this provider.
| Property | Description |
| FirewallType | The protocol used by a proxy-based firewall. |
| FirewallServer | The name or IP address of a proxy-based firewall. |
| FirewallPort | The TCP port for a proxy-based firewall. |
| FirewallUser | The user name to use to authenticate with a proxy-based firewall. |
| FirewallPassword | A password used to authenticate to a proxy-based firewall. |
The protocol used by a proxy-based firewall.
string
"NONE"
This property specifies the protocol that the Cloud will use to tunnel traffic through the FirewallServer proxy. Note that by default, the Cloud connects to the system proxy; to disable this behavior and connect to one of the following proxy types, set ProxyAutoDetect to false.
| Type | Default Port | Description |
| TUNNEL | 80 | When this is set, the Cloud opens a connection to Apache Impala and traffic flows back and forth through the proxy. |
| SOCKS4 | 1080 | When this is set, the Cloud sends data through the SOCKS 4 proxy specified by FirewallServer and FirewallPort and passes the FirewallUser value to the proxy, which determines if the connection request should be granted. |
| SOCKS5 | 1080 | When this is set, the Cloud sends data through the SOCKS 5 proxy specified by FirewallServer and FirewallPort. If your proxy requires authentication, set FirewallUser and FirewallPassword to credentials the proxy recognizes. |
To connect to HTTP proxies, use ProxyServer and ProxyPort. To authenticate to HTTP proxies, use ProxyAuthScheme, ProxyUser, and ProxyPassword.
The name or IP address of a proxy-based firewall.
string
""
This property specifies the IP address, DNS name, or host name of a proxy allowing traversal of a firewall. The protocol is specified by FirewallType: Use FirewallServer with this property to connect through SOCKS or do tunneling. Use ProxyServer to connect to an HTTP proxy.
Note that the Cloud uses the system proxy by default. To use a different proxy, set ProxyAutoDetect to false.
The TCP port for a proxy-based firewall.
int
0
This specifies the TCP port for a proxy allowing traversal of a firewall. Use FirewallServer to specify the name or IP address. Specify the protocol with FirewallType.
The user name to use to authenticate with a proxy-based firewall.
string
""
The FirewallUser and FirewallPassword properties are used to authenticate against the proxy specified in FirewallServer and FirewallPort, following the authentication method specified in FirewallType.
A password used to authenticate to a proxy-based firewall.
string
""
This property is passed to the proxy specified by FirewallServer and FirewallPort, following the authentication method specified by FirewallType.
This section provides a complete list of the Proxy properties you can configure in the connection string for this provider.
| Property | Description |
| ProxyAutoDetect | This indicates whether to use the system proxy settings or not. This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings. |
| ProxyServer | The hostname or IP address of a proxy to route HTTP traffic through. |
| ProxyPort | The TCP port the ProxyServer proxy is running on. |
| ProxyAuthScheme | The authentication type to use to authenticate to the ProxyServer proxy. |
| ProxyUser | A user name to be used to authenticate to the ProxyServer proxy. |
| ProxyPassword | A password to be used to authenticate to the ProxyServer proxy. |
| ProxySSLType | The SSL type to use when connecting to the ProxyServer proxy. |
| ProxyExceptions | A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the ProxyServer . |
This indicates whether to use the system proxy settings or not. This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings.
bool
true
This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings.
To connect to an HTTP proxy, see ProxyServer. For other proxies, such as SOCKS or tunneling, see FirewallType.
The hostname or IP address of a proxy to route HTTP traffic through.
string
""
The hostname or IP address of a proxy to route HTTP traffic through. The Cloud can use the HTTP, Windows (NTLM), or Kerberos authentication types to authenticate to an HTTP proxy.
If you need to connect through a SOCKS proxy or tunnel the connection, see FirewallType.
By default, the Cloud uses the system proxy. If you need to use another proxy, set ProxyAutoDetect to false.
The TCP port the ProxyServer proxy is running on.
int
80
The port the HTTP proxy is running on that you want to redirect HTTP traffic through. Specify the HTTP proxy in ProxyServer. For other proxy types, see FirewallType.
The authentication type to use to authenticate to the ProxyServer proxy.
string
"BASIC"
This value specifies the authentication type to use to authenticate to the HTTP proxy specified by ProxyServer and ProxyPort.
Note that the Cloud will use the system proxy settings by default, without further configuration needed; if you want to connect to another proxy, you will need to set ProxyAutoDetect to false, in addition to ProxyServer and ProxyPort. To authenticate, set ProxyAuthScheme and set ProxyUser and ProxyPassword, if needed.
The authentication type can be one of the following:
If you need to use another authentication type, such as SOCKS 5 authentication, see FirewallType.
A user name to be used to authenticate to the ProxyServer proxy.
string
""
The ProxyUser and ProxyPassword options are used to connect and authenticate against the HTTP proxy specified in ProxyServer.
You can select one of the available authentication types in ProxyAuthScheme. If you are using HTTP authentication, set this to the user name of a user recognized by the HTTP proxy. If you are using Windows or Kerberos authentication, set this property to a user name in one of the following formats:
user@domain domain\user
A password to be used to authenticate to the ProxyServer proxy.
string
""
This property is used to authenticate to an HTTP proxy server that supports NTLM (Windows), Kerberos, or HTTP authentication. To specify the HTTP proxy, you can set ProxyServer and ProxyPort. To specify the authentication type, set ProxyAuthScheme.
If you are using HTTP authentication, additionally set ProxyUser and ProxyPassword to HTTP proxy.
If you are using NTLM authentication, set ProxyUser and ProxyPassword to your Windows password. You may also need these to complete Kerberos authentication.
For SOCKS 5 authentication or tunneling, see FirewallType.
By default, the Cloud uses the system proxy. If you want to connect to another proxy, set ProxyAutoDetect to false.
The SSL type to use when connecting to the ProxyServer proxy.
string
"AUTO"
This property determines when to use SSL for the connection to an HTTP proxy specified by ProxyServer. This value can be AUTO, ALWAYS, NEVER, or TUNNEL. The applicable values are the following:
| AUTO | Default setting. If the URL is an HTTPS URL, the Cloud will use the TUNNEL option. If the URL is an HTTP URL, the component will use the NEVER option. |
| ALWAYS | The connection is always SSL enabled. |
| NEVER | The connection is not SSL enabled. |
| TUNNEL | The connection is through a tunneling proxy. The proxy server opens a connection to the remote host and traffic flows back and forth through the proxy. |
A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the ProxyServer .
string
""
The ProxyServer is used for all addresses, except for addresses defined in this property. Use semicolons to separate entries.
Note that the Cloud uses the system proxy settings by default, without further configuration needed; if you want to explicitly configure proxy exceptions for this connection, you need to set ProxyAutoDetect = false, and configure ProxyServer and ProxyPort. To authenticate, set ProxyAuthScheme and set ProxyUser and ProxyPassword, if needed.
This section provides a complete list of the Logging properties you can configure in the connection string for this provider.
| Property | Description |
| Logfile | A filepath which designates the name and location of the log file. |
| Verbosity | The verbosity level that determines the amount of detail included in the log file. |
| LogModules | Core modules to be included in the log file. |
| MaxLogFileSize | A string specifying the maximum size in bytes for a log file (for example, 10 MB). |
| MaxLogFileCount | A string specifying the maximum file count of log files. |
A filepath which designates the name and location of the log file.
string
""
Once this property is set, the Cloud will populate the log file as it carries out various tasks, such as when authentication is performed or queries are executed. If the specified file doesn't already exist, it will be created.
Connection strings and version information are also logged, though connection properties containing sensitive information are masked automatically.
If a relative filepath is supplied, the location of the log file will be resolved based on the path found in the Location connection property.
For more control over what is written to the log file, you can adjust the Verbosity property.
Log contents are categorized into several modules. You can show/hide individual modules using the LogModules property.
To edit the maximum size of a single logfile before a new one is created, see MaxLogFileSize.
If you would like to place a cap on the number of logfiles generated, use MaxLogFileCount.
The verbosity level that determines the amount of detail included in the log file.
string
"1"
The verbosity level determines the amount of detail that the Cloud reports to the Logfile. Verbosity levels from 1 to 5 are supported. These are detailed in the Logging page.
Core modules to be included in the log file.
string
""
Only the modules specified (separated by ';') will be included in the log file. By default all modules are included.
See the Logging page for an overview.
A string specifying the maximum size in bytes for a log file (for example, 10 MB).
string
"100MB"
When the limit is hit, a new log is created in the same folder with the date and time appended to the end. The default limit is 100 MB. Values lower than 100 kB will use 100 kB as the value instead.
Adjust the maximum number of logfiles generated with MaxLogFileCount.
A string specifying the maximum file count of log files.
int
-1
When the limit is hit, a new log is created in the same folder with the date and time appended to the end and the oldest log file will be deleted.
The minimum supported value is 2. A value of 0 or a negative value indicates no limit on the count.
Adjust the maximum size of the logfiles generated with MaxLogFileSize.
This section provides a complete list of the Schema properties you can configure in the connection string for this provider.
| Property | Description |
| Location | A path to the directory that contains the schema files defining tables, views, and stored procedures. |
| BrowsableSchemas | This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC. |
| Tables | This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC. |
| Views | Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC. |
A path to the directory that contains the schema files defining tables, views, and stored procedures.
string
"%APPDATA%\\CData\\ApacheImpala Data Provider\\Schema"
The path to a directory which contains the schema files for the Cloud (.rsd files for tables and views, .rsb files for stored procedures). The folder location can be a relative path from the location of the executable. The Location property is only needed if you want to customize definitions (for example, change a column name, ignore a column, and so on) or extend the data model with new tables, views, or stored procedures.
If left unspecified, the default location is "%APPDATA%\\CData\\ApacheImpala Data Provider\\Schema" with %APPDATA% being set to the user's configuration directory:
This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.
string
""
Listing the schemas from databases can be expensive. Providing a list of schemas in the connection string improves the performance.
This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC.
string
""
Listing the tables from some databases can be expensive. Providing a list of tables in the connection string improves the performance of the Cloud.
This property can also be used as an alternative to automatically listing views if you already know which ones you want to work with and there would otherwise be too many to work with.
Specify the tables you want in a comma-separated list. Each table should be a valid SQL identifier with any special characters escaped using square brackets, double-quotes or backticks. For example, Tables=TableA,[TableB/WithSlash],WithCatalog.WithSchema.`TableC With Space`.
Note that when connecting to a data source with multiple schemas or catalogs, you will need to provide the fully qualified name of the table in this property, as in the last example here, to avoid ambiguity between tables that exist in multiple catalogs or schemas.
Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC.
string
""
Listing the views from some databases can be expensive. Providing a list of views in the connection string improves the performance of the Cloud.
This property can also be used as an alternative to automatically listing views if you already know which ones you want to work with and there would otherwise be too many to work with.
Specify the views you want in a comma-separated list. Each view should be a valid SQL identifier with any special characters escaped using square brackets, double-quotes or backticks. For example, Views=ViewA,[ViewB/WithSlash],WithCatalog.WithSchema.`ViewC With Space`.
Note that when connecting to a data source with multiple schemas or catalogs, you will need to provide the fully qualified name of the table in this property, as in the last example here, to avoid ambiguity between tables that exist in multiple catalogs or schemas.
This section provides a complete list of the Caching properties you can configure in the connection string for this provider.
| Property | Description |
| AutoCache | Automatically caches the results of SELECT queries into a cache database specified by either CacheLocation or both of CacheConnection and CacheProvider . |
| CacheLocation | Specifies the path to the cache when caching to a file. |
| CacheTolerance | The tolerance for stale data in the cache specified in seconds when using AutoCache . |
| Offline | Use offline mode to get the data from the cache instead of the live source. |
| CacheMetadata | This property determines whether or not to cache the table metadata to a file store. |
Automatically caches the results of SELECT queries into a cache database specified by either CacheLocation or both of CacheConnection and CacheProvider .
bool
false
When AutoCache = true, the Cloud automatically maintains a cache of your table's data in the database of your choice.
When AutoCache = true, the Cloud caches to a simple, file-based cache. You can configure its location or cache to a different database with the following properties:
Specifies the path to the cache when caching to a file.
string
"%APPDATA%\\CData\\ApacheImpala Data Provider"
The CacheLocation is a simple, file-based cache.
If left unspecified, the default location is "%APPDATA%\\CData\\ApacheImpala Data Provider" with %APPDATA% being set to the user's configuration directory:
The tolerance for stale data in the cache specified in seconds when using AutoCache .
int
600
The tolerance for stale data in the cache specified in seconds. This only applies when AutoCache is used. The Cloud checks with the data source for newer records after the tolerance interval has expired. Otherwise, it returns the data directly from the cache.
Use offline mode to get the data from the cache instead of the live source.
bool
false
When Offline = true, all queries execute against the cache as opposed to the live data source. In this mode, certain queries like INSERT, UPDATE, DELETE, and CACHE are not allowed.
This property determines whether or not to cache the table metadata to a file store.
bool
false
As you execute queries with this property set, table metadata in the Apache Impala catalog are cached to the file store specified by CacheLocation if set or the user's home directory otherwise. A table's metadata will be retrieved only once, when the table is queried for the first time.
The Cloud automatically persists metadata in memory for up to two hours when you first discover the metadata for a table or view and therefore, CacheMetadata is generally not required. CacheMetadata becomes useful when metadata operations are expensive such as when you are working with large amounts of metadata or when you have many short-lived connections.
This section provides a complete list of the Miscellaneous properties you can configure in the connection string for this provider.
| Property | Description |
| HTTPPath | The path component of the URL endpoint when using HTTP TransportMode. |
| MaxRows | Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time. |
| Other | These hidden properties are used only in specific use cases. |
| Pagesize | The maximum number of results to return per page from Apache Impala. |
| PseudoColumns | This property indicates whether or not to include pseudo columns as columns to the table. |
| QueryPassthrough | This option passes the query to the Apache Impala server as is. |
| Readonly | You can use this property to enforce read-only access to Apache Impala from the provider. |
| RTK | The runtime key used for licensing. |
| Timeout | The value in seconds until the timeout error is thrown, canceling the operation. |
| UserDefinedViews | A filepath pointing to the JSON configuration file containing your custom views. |
| UseSSL | Specifies whether to use SSL Encryption when connecting to Impala. |
The path component of the URL endpoint when using HTTP TransportMode.
string
"cliservice"
This property is used to specify the path component of the URL endpoint when using HTTP TransportMode.
Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time.
int
-1
Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time.
These hidden properties are used only in specific use cases.
string
""
The properties listed below are available for specific use cases. Normal driver use cases and functionality should not require these properties.
Specify multiple properties in a semicolon-separated list.
| DefaultColumnSize | Sets the default length of string fields when the data source does not provide column length in the metadata. The default value is 2000. |
| ConvertDateTimeToGMT | Determines whether to convert date-time values to GMT, instead of the local time of the machine. |
| RecordToFile=filename | Records the underlying socket data transfer to the specified file. |
The maximum number of results to return per page from Apache Impala.
int
10000
The Pagesize property affects the maximum number of results to return per page from Apache Impala. Setting a higher value may result in better performance at the cost of additional memory allocated per page consumed.
This property indicates whether or not to include pseudo columns as columns to the table.
string
""
This setting is particularly helpful in Entity Framework, which does not allow you to set a value for a pseudo column unless it is a table column. The value of this connection setting is of the format "Table1=Column1, Table1=Column2, Table2=Column3". You can use the "*" character to include all tables and all columns; for example, "*=*".
This option passes the query to the Apache Impala server as is.
bool
false
When this is set, queries are passed through directly to Apache Impala.
You can use this property to enforce read-only access to Apache Impala from the provider.
bool
false
If this property is set to true, the Cloud will allow only SELECT queries. INSERT, UPDATE, DELETE, and stored procedure queries will cause an error to be thrown.
The runtime key used for licensing.
string
""
The RTK property may be used to license a build.
The value in seconds until the timeout error is thrown, canceling the operation.
int
60
If Timeout = 0, operations do not time out. The operations run until they complete successfully or until they encounter an error condition.
If Timeout expires and the operation is not yet complete, the Cloud throws an exception.
A filepath pointing to the JSON configuration file containing your custom views.
string
""
User Defined Views are defined in a JSON-formatted configuration file called UserDefinedViews.json. The Cloud automatically detects the views specified in this file.
You can also have multiple view definitions and control them using the UserDefinedViews connection property. When you use this property, only the specified views are seen by the Cloud.
This User Defined View configuration file is formatted as follows:
For example:
{
"MyView": {
"query": "SELECT * FROM [CData].[Default].Customers WHERE MyColumn = 'value'"
},
"MyView2": {
"query": "SELECT * FROM MyTable WHERE Id IN (1,2,3)"
}
}
Use the UserDefinedViews connection property to specify the location of your JSON configuration file. For example:
"UserDefinedViews", "C:\\Users\\yourusername\\Desktop\\tmp\\UserDefinedViews.json"
Specifies whether to use SSL Encryption when connecting to Impala.
bool
false
Specifies whether to use SSL Encryption when connecting to Impala.
Apache Thrift Client
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