This page provides a guide to Establishing a Connection to Amazon DynamoDB in CData Cloud, as well as information on the available resources, and a reference to the available connection properties.

Connecting to Amazon DynamoDB

Establishing a Connection shows how to authenticate to Amazon DynamoDB and configure any necessary connection properties to create a database in CData Cloud

Accessing Data from CData Cloud Services

Accessing data from Amazon DynamoDB through the available standard services and CData Cloud administration is documented in further details in the CData Cloud Documentation.

Connect to Amazon DynamoDB 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.

Connecting to DynamoDB

Specify the following to connect to data:

• Domain: Set this if you want to use a domain name you have associated with AWS.
• AWSRegion: Set this to the region where your Amazon DynamoDB data is hosted.

Authenticating to DynamoDB

Obtain AWS Keys

1. Sign into the IAM console.
2. In the navigation pane, select Users.
3. To create or manage the access keys for a user, select the user and then go to the Security Credentials tab.

1. Sign into the AWS Management console with the credentials for your root account.
2. Select your account name or number.
3. In the menu that displays, select My Security Credentials.
4. To manage or create root account access keys, click Continue to Security Credentials and expand the "Access Keys" section.

Root Credentials

To authenticate using account root credentials, set these configuration parameters:

• AuthScheme: AwsRootKeys.
• AWSAccessKey: The access key associated with the AWS root account.
• AWSSecretKey: The secret key associated with the AWS root account.

Note: Use of this authentication scheme is discouraged by Amazon for anything but simple tests. The account root credentials have the full permissions of the user, making this the least secure authentication method.

Temporary Credentials

To authenticate using temporary credentials, specify the following:

• AuthScheme: TemporaryCredentials.
• AWSAccessKey: The access key of the IAM user to assume the role for.
• AWSSecretKey: The secret key of the IAM user to assume the role for.
• AWSSessionToken: Your AWS session token, provided with your temporary credentials. For details, see AWS Identity and Access Management User Guide.

The Cloud can now request resources using the same permissions provided by long-term credentials (such as IAM user credentials) for the lifespan of the temporary credentials.

To authenticate using both temporary credentials and an IAM role, set all the parameters described above, and specify these additional parameters:

• AWSRoleARN: Specify the Role ARN for the role you'd like to authenticate with. This prompts the Cloud to retrieve credentials for the specified role.
• AWSExternalId (optional): Only required if you are assuming a role in another AWS account.

EC2 Instances

Set AuthScheme to AwsEC2Roles.

If you are using the Cloud from an EC2 Instance and have an IAM Role assigned to the instance, you can use the IAM Role to authenticate. Since the Cloud automatically obtains your IAM Role credentials and authenticates with them, it is not necessary to specify AWSAccessKey and AWSSecretKey.

If you are also using an IAM role to authenticate, you must additionally specify the following:

• AWSRoleARN: Specify the Role ARN for the role you'd like to authenticate with. This will cause the Cloud to attempt to retrieve credentials for the specified role.
• AWSExternalId (optional): Only required if you are assuming a role in another AWS account.

IMDSv2 Support

The Amazon DynamoDB Cloud now supports IMDSv2. Unlike IMDSv1, the new version requires an authentication token. Endpoints and response are the same in both versions.

In IMDSv2, the Amazon DynamoDB Cloud first attempts to retrieve the IMDSv2 metadata token and then uses it to call AWS metadata endpoints. If it is unable to retrieve the token, the Cloud reverts to IMDSv1.

AWS IAM Roles

Set AuthScheme to AwsIAMRoles.

In many situations, it may be preferable to use an IAM role for authentication instead of the direct security credentials of an AWS root user. If you are specifying the AWSAccessKey and AWSSecretKey of an AWS root user, you may not use roles.

To authenticate as an AWS role, set these properties:

• AWSAccessKey: The access key of the IAM user to assume the role for.
• AWSSecretKey: The secret key of the IAM user to assume the role for.
• AWSRoleARN: Specify the Role ARN for the role you'd like to authenticate with. This will cause the Cloud to attempt to retrieve credentials for the specified role.
• AWSExternalId (optional): Only required if you are assuming a role in another AWS account.

ADFS

To connect to ADFS, set the AuthScheme to ADFS, and set these properties:

• User: The ADFS user.
• Password: The ADFS user's password.
• SSOLoginURL: The SSO provider's login url.

Example connection string:

AuthScheme=ADFS; AWSRegion=Ireland; [email protected]; Password=CH8WerW121235647iCa6; SSOLoginURL='https://adfs.domain.com'; AWSRoleArn=arn:aws:iam::1234:role/ADFS_SSO; AWSPrincipalArn=arn:aws:iam::1234:saml-provider/ADFSProvider; S3StagingDirectory=s3://athena/staging;

ADFS Integrated

The ADFS Integrated flow indicates you are connecting with the currently logged in Windows user credentials. To use the ADFS Integrated flow, do not specify the User and Password, but otherwise follow the same steps in the ADFS guide above.

Okta

To connect to Okta, set the AuthScheme to Okta, and set these properties:

• User: The Okta user.
• Password: The Okta user's password.
• SSOLoginURL: The SSO provider's login URL.

If you are using a trusted application or proxy that overrides the Okta client request OR configuring MFA, you must use combinations of SSOProperties to authenticate using Okta. Set any of the following, as applicable:

• APIToken: When authenticating a user via a trusted application or proxy that overrides the Okta client request context, set this to the API Token the customer created from the Okta organization.
• MFAType: If you have configured the MFA flow, set this to one of the following supported types: OktaVerify, Email, or SMS.
• MFAPassCode: If you have configured the MFA flow, set this to a valid passcode.
  If you set this to empty or an invalid value, the Cloud issues a one-time password challenge to your device or email. After the passcode is received, reopen the connection where the retrieved one-time password value is set to the MFAPassCode connection property.
• MFARememberDevice: True by default. Okta supports remembering devices when MFA is required. If remembering devices is allowed according to the configured authentication policies, the Cloud sends a device token to extend MFA authentication lifetime. If you do not want MFA to be remembered, set this variable to False.

Example connection string:

AuthScheme=Okta; AWSRegion=Ireland; [email protected]; Password=CH8WerW121235647iCa6; SSOLoginURL='https://cdata-us.okta.com/home/amazon_aws/0oa35m8arsAL5f5NrE6NdA356/272'; SSOProperties='ApiToken=01230GGG2ceAnm_tPAf4MhiMELXZ0L0N1pAYrO1VR-hGQSf;'; AWSRoleArn=arn:aws:iam::1234:role/Okta_SSO; AWSPrincipalARN=arn:aws:iam::1234:saml-provider/OktaProvider; S3StagingDirectory=s3://athena/staging;

To connect to PingFederate, set AuthScheme to PingFederate, and set these properties:

• User: The PingFederate user.
• Password: The PingFederate user's password.
• SSOLoginURL: The SSO provider's login url.
• AWSRoleARN (optional): If you have multiple role ARNs, specify the one you want to use for authorization.
• AWSPrincipalARN (optional): If you have multiple principal ARNs, specify the one you want to use for authorization.
• SSOExchangeUrl: The Partner Service Identifier URI configured in your PingFederate server instance under: SP Connections > SP Connection > WS-Trust > Protocol Settings. This should uniquely identify a PingFederate SP Connection, so it is a good idea to set it to your AWS SSO ACS URL. You can find it under AWS SSO > Settings > View Details next to the Authentication field.
• SSOProperties (optional): Authscheme=Basic if you want to include your username and password as an authorization header in requests to Amazon S3.

To enable mutual SSL authentication for SSOLoginURL, the WS-Trust STS endpoint, configure these SSOProperties:

• SSLClientCert
• SSLClientCertType
• SSLClientCertSubject
• SSLClientCertPassword

Example connection string:

authScheme=pingfederate;SSOLoginURL=https://mycustomserver.com:9033/idp/sts.wst;SSOExchangeUrl=https://us-east-1.signin.aws.amazon.com/platform/saml/acs/764ef411-xxxxxx;user=admin;password=PassValue;AWSPrincipalARN=arn:aws:iam::215338515180:saml-provider/pingFederate;AWSRoleArn=arn:aws:iam::215338515180:role/SSOTest2;

Multi-Factor Authentication (MFA)

For users and roles that require multi-factor authentication, specify the following:

• AuthScheme: AwsMFA.
• CredentialsLocation: The location of the settings file where MFA credentials are saved. See the Credentials File Location page under Connection String Options for more information.
• MFASerialNumber: The serial number of the MFA device if one is being used.
• MFAToken: The temporary token available from your MFA device.

• AWSAccessKey: The access key of the IAM user for whom MFA will be issued.
• AWSSecretKey: The secret key of the IAM user whom MFA will be issued.

• AWSRoleARN: Specify the Role ARN for the role you'd like to authenticate with. This will cause the Cloud to attempt to retrieve credentials for the specified role using MFA.
• AWSExternalId (optional): Only required if you are assuming a role in another AWS account.

Note: If you want to control the duration of the temporary credentials, set the TemporaryTokenDuration property (default: 3600 seconds).

Credentials Files

You can use a credentials file to authenticate. Any configurations related to AccessKey/SecretKey authentication, temporary credentials, role authentication, or MFA can be used. To do so, set the following properties to authenticate:

• AuthScheme: AwsCredentialsFile.
• AWSCredentialsFile: The location of your credentials file.
• AWSCredentialsFileProfile (optional): The name of the profile you would like to use from the specified credentials file. If not specified, the default profile is used.

AWS Cognito Credentials

If you want to use the Cloud with a user registered in a User Pool in AWS Cognito, set the following properties to authenticate:

• AuthScheme: Set this to AwsCognitoSrp (recommended). You can also use AwsCognitoBasic.
• AWSCognitoRegion: Set this to the region of the User Pool.
• AWSUserPoolId: Set this to the User Pool Id.
• AWSUserPoolClientAppId: Set this to the User Pool Client App Id.
• AWSUserPoolClientAppSecret: Set this to the User Pool Client Secret.
• AWSIdentityPoolId: Set this to the Identity Pool Id of the Identity Pool that is linked with the User Pool.
• User: Set this to the username of the user registered in the User Pool.
• Password: Set this to the password of the user registered in the User Pool.

Inferring the Data Type

You can use the following properties to configure automatic data type detection, which is enabled by default.

• TypeDetectionScheme: You can use this property to enable or disable automatic type detection based on the value specified in RowScanDepth.
• RowScanDepth: This property determines the number of rows that will be scanned to determine column data types.
• IgnoreTypes: The data types that should be ignored and resolve to varchar data types. By default, Date, Time, and Datetime types are ignored. This is because Amazon DynamoDB does not support them as types. Any filtering of these columns may be done only as their original varchar data type.

Fine Tuning Data Access

You can use the following properties to gain greater control over Amazon DynamoDB API features and the strategies the Cloud uses to surface them:

• UseSimpleNames: Amazon DynamoDB supports attribute names with special characters that many database-oriented tools do not support.

  In addition, Amazon DynamoDB table names can include dots and dashes -- the Cloud interprets dots within table names as hierarchy separators that enable you to drill down to nested fields, similar to XPath.

  You can use this property to replace any nonalphanumeric character with an underscore.

• SeparatorCharacter: You can use this property to more easily access nested fields when Querying Documents and Lists; specify the hierarchy separator with this property. By default, this character is the '.' (dot) character.

Setting a Retry Interval

You can set the following properties to retry queries instead of returning a temporary error such as "maximum throughput exceeded":

• RetryWaitTime: The minimum number of milliseconds the Cloud will wait to retry a request.
• MaximumRequestRetries: The maximum number of times to retry a request.

The CData Cloud also has two seperate APIs that may be used depending on the query, PartiQL and Scan. The API that is used depends on the query that is executed.

PartiQL

Using Paging Effectively

You can use the Pagesize property to optimize use of your provisioned throughput, based on the size of your items and Amazon DynamoDB's 1MB page size. Set this property to the number of items to return.

Generally, a smaller page size reduces spikes in throughput that cause throttling. A smaller page size also inserts pauses between requests. This interval evens out the distribution of requests and allows more requests to be successful by avoiding throttling.

Scans

The ThreadCount connection property may be set to influence how many threads will be used when executing a Scan request. Using more threads will cause more memory to be taken up, but will result in faster results per thread. The default is 4. This works best on tables where a high or variable throughput is provisioned.

In cases where the maximum throughput for a table would be exceeded on a single thread, there is no benefit to using a Scan over the single threaded PartiQL API. The Amazon DynamoDB will simply throttle all threads until the maximum throughput is no longer exceeded.

We recommend using predefined roles for services rather than creating custom IAM policies. Predefined roles for Amazon DynamoDB are

• AmazonDynamoDBReadOnlyAccess-grants read-only access to DynamoDB resources through the AWS Management Console.
• AmazonDynamoDBFullAccess-grants full access to DynamoDB resources through the AWS Management Console.

          "Resource": [
              "arn:aws:dynamodb:us-east-1:987654321098:table/Customers",
              "arn:aws:dynamodb:us-east-1:987654321098:table/Orders"
          ]

      {
          "Effect": "Allow",
          "Action": [
              "dynamodb:DescribeTable"
          ],
          "Resource": [
              "arn:aws:dynamodb:us-east-1:987654321098:table/Customers",
              "arn:aws:dynamodb:us-east-1:987654321098:table/Orders"
          ]
      }

"Resource": "arn:aws:dynamodb:us-east-1:987654321098:table/*"

Amazon DynamoDB is a schemaless database that provides high performance, availability, and scalability. These features are not necessarily incompatible with a standards-compliant query language like SQL-92. In this section we will show various schemes that the Cloud offers to bridge the gap with relational SQL and a document database.

The Cloud models the schemaless Amazon DynamoDB tables into relational tables and translates SQL queries into Amazon DynamoDB queries to get the requested data.

The Automatic Schema Discovery scheme automatically finds the data types in a Amazon DynamoDB table by scanning a configured number of rows of the table. You can use RowScanDepth, FlattenArrays, and FlattenObjects to control the relational representation of the tables in Amazon DynamoDB.

The Cloud automatically infers a relational schema by inspecting a series of Amazon DynamoDB documents in a collection. You can use the RowScanDepth property to define the number of documents the Cloud will scan to do so. The columns identified during the discovery process depend on the FlattenArrays and FlattenObjects properties.

Flattening Objects

If FlattenObjects is set, all nested objects will be flattened into a series of columns. For example, consider the following document:

{
  id: 12,
  name: "Lohia Manufacturers Inc.",
  address: {street: "Main Street", city: "Chapel Hill", state: "NC"},
  offices: ["Chapel Hill", "London", "New York"],
  annual_revenue: 35,600,000
}

If FlattenObjects is not set, then the address.street, address.city, and address.state columns will not be broken apart. The address column of type string will instead represent the entire object. Its value would be {street: "Main Street", city: "Chapel Hill", state: "NC"}. See JSON Functions for more details on working with JSON aggregates.

You can change the separator character in the column name from a dot by setting SeparatorCharacter.

Flattening Arrays

The FlattenArrays property can be used to flatten array values into columns of their own. This is only recommended for arrays that are expected to be short, for example the coordinates below:

"coord": [ -73.856077, 40.848447 ]

It is best to leave other unbounded arrays as they are and piece out the data for them as needed using JSON Functions.

It is possible to retrieve an array of objects as if it were a separate table. Take the following JSON structure from the restaurants table for example:

{
  "restaurantid" : "30075445",
  "address" : {
    "building" : "1007",
    "coord" : [-73.856077, 40.848447],
    "street" : "Morris Park Ave",
    "zipcode" : "10462"
  },
  "borough" : "Bronx",
  "cuisine" : "Bakery",
  "grades" : [{
      "date" : 1393804800000,
      "grade" : "B",
      "score" : 2
    }, {
      "date" : 1378857600000,
      "grade" : "A",
      "score" : 6
    }, {
      "date" : 1358985600000,
      "grade" : "A",
      "score" : 10
    }],
  "name" : "Morris Park Bake Shop"
}

SELECT * FROM [restaurants.grades]

The grades array could also be nested some levels deeper. In that case, the same syntax should be used:

SELECT * FROM [restaurants.cuisine.bakery.grades]

{
  "restaurantid" : "30075445",
  "reviews": [
   {
    "grades": [
     {
      "date": 1393804800000,
      "score": 2,
      "grade": "B"
     },
     {
      "date": 1378857600000,
      "score": 6,
      "grade": "A"
     },
     {
      "date": 1358985600000,
      "score": 10,
      "grade": "A"
     }]
    }],
  "name" : "Morris Park Bake Shop"
}

SELECT * FROM [restaurants.reviews.\[0\].grades]

The Cloud can return JSON structures as column values. The Cloud enables you to use standard SQL functions to work with these JSON structures. The examples in this section use the following array:

[
     { "grade": "A", "score": 2 },
     { "grade": "A", "score": 6 },
     { "grade": "A", "score": 10 },
     { "grade": "A", "score": 9 },
     { "grade": "B", "score": 14 }
]

JSON_EXTRACT

SELECT Name, JSON_EXTRACT(grades,'[0].grade') AS Grade, JSON_EXTRACT(grades,'[0].score') AS Score FROM Students;

JSON_COUNT

SELECT Name, JSON_COUNT(grades,'[x]') AS NumberOfGrades FROM Students;

JSON_SUM

SELECT Name, JSON_SUM(score,'[x].score') AS TotalScore FROM Students;

JSON_MIN

SELECT Name, JSON_MIN(score,'[x].score') AS LowestScore FROM Students;

JSON_MAX

SELECT Name, JSON_MAX(score,'[x].score') AS HighestScore FROM Students;

DOCUMENT

The DOCUMENT function can be used to retrieve the entire document as a JSON string. See the following query and its result as an example:

SELECT DOCUMENT(*) FROM Customers;

{ "id": 12, "name": "Lohia Manufacturers Inc.", "address": { "street": "Main Street", "city": "Chapel Hill", "state": "NC"}, "offices": [ "Chapel Hill", "London", "New York" ], "annual_revenue": 35,600,000 }

Because Amazon DynamoDB is a NoSQL data source, queries need to be handled a bit differently than standard relational databases.

Value-Sensitive Queries

The lack of a required data type for a given column means that you could store different types of data in a single column. For instance, one row could have a String called EmailAddresses and another could have a StringSet also called EmailAddresses. For these and other kinds of cases, the Cloud largely determines what data type to use based on the values in the query.

For instance, say you have an Items table where the PartNumber could store either a String or a Number. To get back a part with the PartNumber of the number value 12345, you would issue the following query:

SELECT Name, Location, Quantity, PartNumber FROM Items WHERE PartNumber = 12345

Alternatively, the PartNumber could have been stored as the string "12345". To get back a part with the PartNumber of the literal string 12345, issue the following query:

SELECT Name, Location, Quantity, PartNumber FROM Items WHERE PartNumber = '12345'

Detected Column Data Type

If a value is not obvious based purely on the detected data type, the Cloud compares it to the autodetected column. For instance, if you want to insert a column called Coordinates into the Location table, your INSERT would look like:

INSERT INTO Locations (Address, Coordinates) VALUES ('123 Fake Street', '[40.7127, 74.0059]')

If a Coordinates column was not autodetected when scanning the Locations table, the data type of the inserted value is used.

In this case, we could still resolve that the INSERT is a NumberSet, but it will cost a bit more overhead to do this.

Count

Amazon DynamoDB supports 2 different methods of of using the COUNT aggregate function. To simply return the number of Items in you table, issue the following query:

SELECT COUNT(*) FROM MyTable

Issuing the below example queries will instead scan the full table for count:

SELECT COUNT(*) FROM MyTable WHERE MyInt > 10
SELECT COUNT(MyInt) FROM MyTable

Amazon DynamoDB documents and lists are supported with the CData Cloud. You can access documents and lists directly at the root level or use the '.' character as a hierarchy divider to drill down to documents and lists.

Reporting Values in Documents and Lists

When data types are autodetected, they are reported down to the lowest level that can be reliably detected. For instance, a document called Customer with a child called Address and a child on Address called Street would be represented by the column Customer.Address.Street.

However, this process does not apply to Lists since a list could have any number of entries. Once a List or a Set is detected, additional values are not reported as being available in the table schema.

Getting Back Unreported Values

If there are attributes that frequently do not have a value and thus are not autodetected, these can still be retrieved by specifying the correct path to them. For instance, to get the Special attribute from the Customer document:

SELECT [Customer.Address.Street], [Customer.Special] FROM MyTable

SELECT [MyList.0], [MyList.1.Email], [MyList.1.Age] FROM MyTable

Inserting Documents and Lists

INSERTs in Amazon DynamoDB require that the full object is specified. Insert a document or list at the root. Pass in the full JSON aggregate. For instance:

INSERT INTO MyTable (PrimaryKey, EmailAddresses, Address, MyList) VALUES ('uniquekey', '["[email protected]", "[email protected]"]', '{"Street":"123 Fake Street", "City":"Chapel Hill", "Zip":"27713"}', '[{"S":"somestr"},{"NS":[1,2]},{"N":4}]')

Updating Documents and Lists

Updates are supported using the same syntax that is available during selects. Documents and Lists can be specified using the '.' character to specify hierarchy. For instance:

UPDATE MyTable SET [EmailAddress.0]='[email protected]', [EmailAddress.1]='[email protected]', [Address.Street]='123 Fake Street', [Address.City]='Chapel Hill', [Address.Zip]='27713', [MyList.0]='somestr', [MyList.1]='[1,2]', [MyList.2]=4 WHERE PrimaryKey='uniquekey'

Customizing the SSL Configuration

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.

Connecting Through a Firewall or Proxy

HTTP Proxies

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.

Other Proxies

Set the following properties:

• To use a proxy-based firewall, set FirewallType, FirewallServer, and FirewallPort.
• To tunnel the connection, set FirewallType to TUNNEL.
• To authenticate, specify FirewallUser and FirewallPassword.
• To authenticate to a SOCKS proxy, additionally set FirewallType to SOCKS5.

The Cloud allows you to access data in Amazon DynamoDB using a standard database-like interface. Amazon DynamoDB is a highly scalable NoSQL cloud database that is very different from a regular database. In this section we describe how we model schemaless Amazon DynamoDB tables as regular Tables and Stored Procedures.

The Cloud can dynamically detect schemas at connection time. See Automatic Schema Discovery for more information on defining schemas implicitly at connection time. This method is useful if the structure of your data is volatile.

The list of tables is dynamically retrieved from your Amazon DynamoDB account. You can use the stored procedure to create a new table, or you can create a table using the Amazon Web Services Admin Console.

Because DynamoDB tables are partitioned based on their key, you should take care in selecting a proper key based on the query requirements of your table. Refer to the documentation for DynamoDB for more information about using best practices to model data in DynamoDB tables. DynamoDB supports two types of primary keys:

• Hash Primary Key: This is a single-column key.
• Hash and Range Primary Key: This is a two-column key that includes a hash column and a range column.

Since Amazon DynamoDB tables are schemaless, the Cloud offers the following two mechanisms to uncover the schema.

Dynamic Schemas

The columns of a table are dynamically determined by scanning data in the first few rows. You can adjust the number of rows that are used by modifying the RowScanDepth property. In addition to the name of the column, the row scan also determines the data type. The following table shows how the different data types supported by Amazon DynamoDB are modeled in the Cloud.

Static Schemas

Instead of using dynamically discovered schemas, you can define your own schemas. This will give you more control over the projected columns and also enable you to use other data types such as boolean, datetime, etc. Refer to the CreateSchema Stored Procedure in order to create your own schema. You can simply specify the FileName (fullpath) and TableName of the new schema file, which should match with the name of the Amazon DynamoDB table, and edit the column listing to use it for your own table.

Schemaless Operations

While the schema of the table is necessary to report metadata, data may be selected, inserted, updated, or deleted from columns that do not exist in the schema. Columns that do not already exist in the table schema will have their data types dynamically determined based on the data that is specified. See DynamoDB Queries for more information.

Stored procedures are function-like interfaces that extend the functionality of the Cloud beyond simple SELECT/INSERT/UPDATE/DELETE operations with Amazon DynamoDB.

Stored procedures accept a list of parameters, perform their intended function, and then return any relevant response data from Amazon DynamoDB, along with an indication of whether the procedure succeeded or failed.

CData Cloud - Amazon DynamoDB Stored Procedures

Creates a table in DynamoDB.

Input

Result Set Columns

You can query the system tables described in this section to access schema information, information on data source functionality, and batch operation statistics.

Schema Tables

The following tables return database metadata for Amazon DynamoDB:

• sys_catalogs: Lists the available databases.
• sys_schemas: Lists the available schemas.
• sys_tables: Lists the available tables and views.
• sys_tablecolumns: Describes the columns of the available tables and views.
• sys_procedures: Describes the available stored procedures.
• sys_procedureparameters: Describes stored procedure parameters.
• sys_keycolumns: Describes the primary and foreign keys.
• sys_indexes: Describes the available indexes.

Data Source Tables

The following tables return information about how to connect to and query the data source:

• sys_connection_props: Returns information on the available connection properties.
• sys_sqlinfo: Describes the SELECT queries that the Cloud can offload to the data source.

Query Information Tables

The following table returns query statistics for data modification queries, including batch operations::

• sys_identity: Returns information about batch operations or single updates.

Lists the available databases.

The following query retrieves all databases determined by the connection string:

SELECT * FROM sys_catalogs

Columns

Lists the available schemas.

The following query retrieves all available schemas:

          SELECT * FROM sys_schemas
          

Columns

Lists the available tables.

The following query retrieves the available tables and views:

          SELECT * FROM sys_tables
          

Columns

Describes the columns of the available tables and views.

The following query returns the columns and data types for the Account table:

SELECT ColumnName, DataTypeName FROM sys_tablecolumns WHERE TableName='Account' 

Columns

Lists the available stored procedures.

The following query retrieves the available stored procedures:

          SELECT * FROM sys_procedures
          

Columns

Describes stored procedure parameters.

The following query returns information about all of the input parameters for the CreateSchema stored procedure:

SELECT * FROM sys_procedureparameters WHERE ProcedureName='CreateSchema' AND Direction=1 OR Direction=2

Columns

Describes the primary and foreign keys.

The following query retrieves the primary key for the Account table:

         SELECT * FROM sys_keycolumns WHERE IsKey='True' AND TableName='Account' 
          

Columns

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'
          

Columns

Describes the primary keys.

The following query retrieves the primary keys from all tables and views:

         SELECT * FROM sys_primarykeys
          

Columns

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'
          

Columns

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:amazondynamodb: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 <> ''

Columns

Describes the SELECT query processing that the Cloud can offload to the data source.

See SQL Compliance for SQL syntax details.

Discovering the Data Source's SELECT Capabilities

Below is an example data set of SQL capabilities. Some aspects of SELECT functionality are returned in a comma-separated list if supported; otherwise, the column contains NO.

The following query retrieves the operators that can be used in the WHERE clause:

SELECT * FROM sys_sqlinfo WHERE Name = 'SUPPORTED_OPERATORS'

Columns

Returns information about attempted modifications.

The following query retrieves the Ids of the modified rows in a batch operation:

         SELECT * FROM sys_identity
          

Columns

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.

Connection

AWS Authentication

SSO

SSL

Logging

Schema

Miscellaneous

This section provides a complete list of the Connection properties you can configure in the connection string for this provider.

When this property is set to true, AWSLakeFormation service will be used to retrieve temporary credentials, which enforce access policies against the user based on the configured IAM role. The service can be used when authenticating through OKTA, ADFS, AzureAD, PingFederate, while providing a SAML assertion.

Data Type

bool

Default Value

false

Remarks

When this property is set to true, AWSLakeFormation service will be used to retrieve temporary credentials, which enforce access policies against the user based on the configured IAM role. The service can be used when authenticating through OKTA, ADFS, AzureAD, PingFederate, while providing a SAML assertion.

This section provides a complete list of the AWS Authentication properties you can configure in the connection string for this provider.

The scheme used for authentication. Accepted entries are: Auto, , AwsRootKeys , AwsIAMRoles , AwsEC2Roles , AwsMFA , ADFS, Okta, PingFederate , AwsCredentialsFile , AwsCognitoBasic , AwsCognitoSrp.

Data Type

string

Default Value

"AwsRootKeys"

Remarks

Use the following options to select your authentication scheme:

• Auto: Set this to have the Cloud attempt to automatically resolve the proper authentication scheme to use based on the other connection properties specified.
• TemporaryCredentials: Set this to leverage temporary security credentials alongside a session token to connect.
• AwsRootKeys: Set this to use the root user access key and secret. Useful for quickly testing, but production use cases are encouraged to use something with narrowed permissions.
• AwsIAMRoles: Set to use IAM Roles for the connection.
• AwsEC2Roles: Set this to automatically use IAM Roles assigned to the EC2 machine the CData Cloud is currently running on.
• AwsMFA: Set to use multi factor authentication.
• Okta: Set to use a single sign on connection with OKTA as the identity provider.
• ADFS: Set to use a single sign on connection with ADFS as the identity provider.
• PingFederate: Set to use a single sign on connection with PingFederate as the identity provider.
• AwsCredentialsFile: Set to use a credential file for authentication.
• AwsCognitoSrp: Set to use Cognito based authentication. This is recommended over AwsCognitoBasic because this option does NOT send the password to the server for authentication, instead it uses the SRP protocol.
• AwsCognitoBasic: Set to use Cognito based authentication.

Your AWS domain name. You can optionally choose to associate your domain name with AWS.

Data Type

string

Default Value

"amazonaws.com"

Remarks

If you do not have a unique AWS domain name, leave this value specified as amazonaws.com.

Your AWS account access key. This value is accessible from your AWS security credentials page.

Data Type

string

Default Value

""

Remarks

Your AWS account access key. This value is accessible from your AWS security credentials page:

1. Sign into the AWS Management console with the credentials for your root account.
2. Select your account name or number and select My Security Credentials in the menu that is displayed.
3. Click Continue to Security Credentials and expand the Access Keys section to manage or create root account access keys.

Your AWS account secret key. This value is accessible from your AWS security credentials page.

Data Type

string

Default Value

""

Remarks

Your AWS account secret key. This value is accessible from your AWS security credentials page:

1. Sign into the AWS Management console with the credentials for your root account.
2. Select your account name or number and select My Security Credentials in the menu that is displayed.
3. Click Continue to Security Credentials and expand the Access Keys section to manage or create root account access keys.

The Amazon Resource Name of the role to use when authenticating.

Data Type

string

Default Value

""

Remarks

When authenticating outside of AWS, it is common to use a Role for authentication instead of your direct AWS account credentials. Entering the AWSRoleARN will cause the CData Cloud to perform a role based authentication instead of using the AWSAccessKey and AWSSecretKey directly. The AWSAccessKey and AWSSecretKey must still be specified to perform this authentication. You cannot use the credentials of an AWS root user when setting RoleARN. The AWSAccessKey and AWSSecretKey must be those of an IAM user.

The hosting region for your Amazon Web Services.

Possible Values

Data Type

string

Default Value

"NORTHERNVIRGINIA"

Remarks

The hosting region for your Amazon Web Services. Available values are OHIO, NORTHERNVIRGINIA, NORTHERNCALIFORNIA, OREGON, CAPETOWN, HONGKONG, JAKARTA, MUMBAI, OSAKA, SEOUL, SINGAPORE, SYDNEY, TOKYO, CENTRAL, BEIJING, NINGXIA, FRANKFURT, IRELAND, LONDON, MILAN, PARIS, STOCKHOLM, ZURICH, BAHRAIN, UAE, SAOPAULO, GOVCLOUDEAST, and GOVCLOUDWEST.

Your AWS session token.

Data Type

string

Default Value

""

Remarks

Your AWS session token. This value can be retrieved in different ways. See this link for more info.

A unique identifier that might be required when you assume a role in another account.

Data Type

string

Default Value

""

Remarks

A unique identifier that might be required when you assume a role in another account.

The serial number of the MFA device if one is being used.

Data Type

string

Default Value

""

Remarks

You can find the device for an IAM user by going to the AWS Management Console and viewing the user's security credentials. For virtual devices, this is actually an Amazon Resource Name (such as arn:aws:iam::123456789012:mfa/user).

The temporary token available from your MFA device.

Data Type

string

Default Value

""

Remarks

If MFA is required, this value will be used along with the MFASerialNumber to retrieve temporary credentials to login. The temporary credentials available from AWS will only last up to 1 hour by default (see TemporaryTokenDuration). Once the time is up, the connection must be updated to specify a new MFA token so that new credentials may be obtained.

The amount of time (in seconds) a temporary token will last.

Data Type

string

Default Value

"3600"

Remarks

Temporary tokens are used with both MFA and Role based authentication. Temporary tokens will eventually time out, at which time a new temporary token must be obtained. For situations where MFA is not used, this is not a big deal. The CData Cloud will internally request a new temporary token once the temporary token has expired.

However, for MFA required connection, a new MFAToken must be specified in the connection to retrieve a new temporary token. This is a more intrusive issue since it requires an update to the connection by the user. The maximum and minimum that can be specified will depend largely on the connection being used.

For Role based authentication, the minimum duration is 900 seconds (15 minutes) while the maximum if 3600 (1 hour). Even if MFA is used with role based authentication, 3600 is still the maximum.

For MFA authentication by itself (using an IAM User or root user), the minimum is 900 seconds (15 minutes), the maximum is 129600 (36 hours).

The hosting region for AWS Cognito.

Possible Values

Data Type

string

Default Value

"NORTHERNVIRGINIA"

Remarks

The hosting region for AWS Cognito. Available values are OHIO, NORTHERNVIRGINIA, NORTHERNCALIFORNIA, OREGON, CAPETOWN, HONGKONG, MUMBAI, OSAKA, SEOUL, SINGAPORE, SYDNEY, TOKYO, CENTRAL, BEIJING, NINGXIA, FRANKFURT, IRELAND, LONDON, MILAN, PARIS, STOCKHOLM, BAHRAIN, SAOPAULO, GOVCLOUDEAST, and GOVCLOUDWEST.

The User Pool Id.

Data Type

string

Default Value

""

Remarks

You can find this in AWS Cognito -> Manage User Pools -> select your user pool -> General settings -> Pool Id.

The User Pool Client App Id.

Data Type

string

Default Value

""

Remarks

You can find this in AWS Cognito -> Manage Identity Pools -> select your user pool -> General settings -> App clients -> App client Id.

Optional. The User Pool Client App Secret.

Data Type

string

Default Value

""

Remarks

You can find this in AWS Cognito -> Manage Identity Pools -> select your user pool -> General settings -> App clients -> App client secret.

The Identity Pool Id.

Data Type

string

Default Value

""

Remarks

You can find this in AWS Cognito -> Manage Identity Pools -> select your identity pool -> Edit identity pool -> Identity Pool Id

This section provides a complete list of the SSO properties you can configure in the connection string for this provider.

The IDP user used to authenticate the IDP via SSO.

Data Type

string

Default Value

""

Remarks

Together with Password, this field is used to authenticate in SSO connections against the Amazon DynamoDB server.

The password used to authenticate the IDP user via SSO.

Data Type

string

Default Value

""

Remarks

The User and Password are together used in SSO connections to authenticate with the server.

The identity provider's login URL.

Data Type

string

Default Value

""

Remarks

The identity provider's login URL.

Additional properties required to connect to the identity provider in a semicolon-separated list.

Data Type

string

Default Value

""

Remarks

Additional properties required to connect to the identity provider in a semicolon-separated list. SSOProperties is used in conjunction with the the AWSRoleARN and AWSPrincipalARN. The following section provides an example using the OKTA identity provider.

ADFS

To connect to ADFS, set the AuthScheme to ADFS, and set these properties:

• User: The ADFS user.
• Password: The ADFS user's password.
• SSOLoginURL: The SSO provider's login url.

Example connection string:

AuthScheme=ADFS; AWSRegion=Ireland; [email protected]; Password=CH8WerW121235647iCa6; SSOLoginURL='https://adfs.domain.com'; AWSRoleArn=arn:aws:iam::1234:role/ADFS_SSO; AWSPrincipalArn=arn:aws:iam::1234:saml-provider/ADFSProvider; S3StagingDirectory=s3://athena/staging;

ADFS Integrated

The ADFS Integrated flow indicates you are connecting with the currently logged in Windows user credentials. To use the ADFS Integrated flow, do not specify the User and Password, but otherwise follow the same steps in the ADFS guide above.

Okta

To connect to Okta, set the AuthScheme to Okta, and set these properties:

• User: The Okta user.
• Password: The Okta user's password.
• SSOLoginURL: The SSO provider's login URL.

If you are using a trusted application or proxy that overrides the Okta client request OR configuring MFA, you must use combinations of SSOProperties to authenticate using Okta. Set any of the following, as applicable:

• APIToken: When authenticating a user via a trusted application or proxy that overrides the Okta client request context, set this to the API Token the customer created from the Okta organization.
• MFAType: If you have configured the MFA flow, set this to one of the following supported types: OktaVerify, Email, or SMS.
• MFAPassCode: If you have configured the MFA flow, set this to a valid passcode.
  If you set this to empty or an invalid value, the Cloud issues a one-time password challenge to your device or email. After the passcode is received, reopen the connection where the retrieved one-time password value is set to the MFAPassCode connection property.
• MFARememberDevice: True by default. Okta supports remembering devices when MFA is required. If remembering devices is allowed according to the configured authentication policies, the Cloud sends a device token to extend MFA authentication lifetime. If you do not want MFA to be remembered, set this variable to False.

Example connection string:

AuthScheme=Okta; AWSRegion=Ireland; [email protected]; Password=CH8WerW121235647iCa6; SSOLoginURL='https://cdata-us.okta.com/home/amazon_aws/0oa35m8arsAL5f5NrE6NdA356/272'; SSOProperties='ApiToken=01230GGG2ceAnm_tPAf4MhiMELXZ0L0N1pAYrO1VR-hGQSf;'; AWSRoleArn=arn:aws:iam::1234:role/Okta_SSO; AWSPrincipalARN=arn:aws:iam::1234:saml-provider/OktaProvider; S3StagingDirectory=s3://athena/staging;

The URL used for consuming the SAML response and exchanging it for service specific credentials.

Data Type

string

Default Value

""

Remarks

The CData Cloud will use the URL specified here to consume a SAML response and exchange it for service specific credentials. The retrieved credentials are the final piece during the SSO connection that are used to communicate with Amazon DynamoDB.

This section provides a complete list of the SSL properties you can configure in the connection string for this provider.

The certificate to be accepted from the server when connecting using TLS/SSL.

Data Type

string

Default Value

""

Remarks

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:

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 Logging properties you can configure in the connection string for this provider.

The verbosity level that determines the amount of detail included in the log file.

Data Type

string

Default Value

"1"

Remarks

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.

This section provides a complete list of the Schema properties you can configure in the connection string for this provider.

This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.

Data Type

string

Default Value

""

Remarks

Listing the schemas from databases can be expensive. Providing a list of schemas in the connection string improves the performance.

This section provides a complete list of the Miscellaneous properties you can configure in the connection string for this provider.

A boolean indicating if secondary indexes should be automatically detected based on the query used.

Data Type

bool

Default Value

true

Remarks

In DynamoDB, you can use secondary indexes to more quickly select data from a given table. By default, we attempt to automatically detect an index to use based on the query criteria. However, this may not always be desirable. To turn off index detecting logic, set the property to false, or if you have control over the query and would prefer to specify the index yourself, use the SecondaryIndexName pseudo column to specify which index to use (if any).

By default, nested arrays are returned as strings of JSON. The FlattenArrays property can be used to flatten the elements of nested arrays into columns of their own. Set FlattenArrays to the number of elements you want to return from nested arrays.

Data Type

string

Default Value

""

Remarks

By default, nested arrays are returned as strings of JSON. The FlattenArrays property can be used to flatten the elements of nested arrays into columns of their own. This is only recommended for arrays that are expected to be short.

Set FlattenArrays to the number of elements you want to return from nested arrays. The specified elements are returned as columns. The zero-based index is concatenated to the column name. Other elements are ignored.

For example, you can return an arbitrary number of elements from an array of strings:

["FLOW-MATIC","LISP","COBOL"]

Set FlattenObjects to true to flatten object properties into columns of their own. Otherwise, objects nested in arrays are returned as strings of JSON.

Data Type

bool

Default Value

true

Remarks

Set FlattenObjects to true to flatten object properties into columns of their own. Otherwise, objects nested in arrays are returned as strings of JSON. The property name is concatenated onto the object name with an underscore to generate the column name.

For example, you can flatten the nested objects below at connection time:

[
     { "grade": "A", "score": 2 },
     { "grade": "A", "score": 6 },
     { "grade": "A", "score": 10 },
     { "grade": "A", "score": 9 },
     { "grade": "B", "score": 14 }
]

Set FlexibleSchema to true to scan for additional metadata on the query result set. Otherwise, the metadata will remain the same.

Data Type

bool

Default Value

true

Remarks

Set FlexibleSchema to true to scan for additional metadata on the query result set. Otherwise, the metadata will remain the same.

Removes support for the specified types. For example, Time. These types will then be reported as strings instead.

Data Type

string

Default Value

"Datetime,Date,Time"

Remarks

Removes support for the specified types. For example, Time. These types will then be reported as strings instead.

The maximum number of times to retry a request.

Data Type

string

Default Value

"4"

Remarks

MaximumRequestRetries is the maximum number of times the Cloud will retry a request when the problem has been detected as temporary (errors like "unknown error", network issues, and exceeding the maximum threshold per table). In this case on the first retry the Cloud will back off and wait for the amount of time designated by RetryWaitTime. If that request fails, the Cloud will double the time and then double again until the Cloud has exhausted the available retries.

For example, if RetryWaitTime is set to 2 seconds and MaximumRequestRetries is set to 5, the wait times will be as follows: 0 -> 2 -> 4 -> 8 -> 16 -> 32.

Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.

Data Type

int

Default Value

-1

Remarks

Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.

Configures the maximum number of items that Amazon DynamoDB evaluates per API request.

Data Type

int

Default Value

-1

Remarks

Configures the maximum number of items that Amazon DynamoDB evaluates (not necessarily the number of matching items) per api request. If Amazon DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, along with a pagination token used to pull the rest of the data. Also, if the processed dataset size exceeds 1 MB before Amazon DynamoDB reaches this page size limit, it stops the operation and returns the matching values up to the limit. The default value is -1 which lets the server calculate the maximum page size.

This property indicates whether or not to include pseudo columns as columns to the table.

Data Type

string

Default Value

""

Remarks

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 property indicates how the driver will retrieve the results.

Possible Values

Data Type

string

Default Value

"Adaptive"

Remarks

• Adaptive - Determine which mode to use depending on ThreadCount and the SQL statement filters.
• PartiQL - Rebuilds the supported parts of the given SQL statement in the PartiQL equivalent.
• SCAN - Full scan the table in parallel (number of threads is controled by ThreadCount).

The minimum number of milliseconds the provider will wait to retry a request.

Data Type

string

Default Value

"2000"

Remarks

The value of this property is doubled on every retry to determine how long to wait until the next retry. Specify the maximum number of retries with MaximumRequestRetries.

The maximum number of rows to scan to look for the columns available in a table.

Data Type

int

Default Value

50

Remarks

The columns in a table must be determined by scanning table rows. This value determines the maximum number of rows that will be scanned.

Setting a high value may decrease performance. Setting a low value may prevent the data type from being determined properly, especially when there is null data.

The character or characters used to denote hierarchy.

Data Type

string

Default Value

"."

Remarks

In order to flatten out structures such as Maps and List attributes in DynamoDB, we need some specifier that states what the separation is between those columns and other columns. If this value is "." and a column comes back with the name address.city, this indicates that there is a mapped attribute with a child called city. If your data has columns that already use a single period within the attribute name, set the SeparatorCharacter to a different character or characters.

The number of threads to use when selecting data via a parallel scan. Setting ThreadCount to 1 will disable parallel scans.

Data Type

string

Default Value

"5"

Remarks

Parallel scans allow data to be retrieved faster by splitting up the retrieval process across multiple threads. This can greatly improve performance when scanning data in Amazon DynamoDB. However, this will also consume your read units for a table much faster than a single thread. Consider your available cores, bandwidth, and read units for your tables before increasing the ThreadCount.

The value in seconds until the timeout error is thrown, canceling the operation.

Data Type

int

Default Value

60

Remarks

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.

Determines how to determine the data type of columns.

Possible Values

Data Type

string

Default Value

"RowScan"

Remarks

When enabled the provider will use BatchWriteItem operation for handling updates and INSERTs. By default, the provider uses ExecuteStatement/BatchExecuteStatement operation. You need to enable BatchWriteItem only when inserting/updating binary/binary-set data. ExecuteStatement/BatchExecuteStatement doesn't support manipulating binary fields.

Data Type

bool

Default Value

false

Remarks

When enabled the provider will use BatchWriteItem operation for handling updates and INSERTs. By default, the provider uses ExecuteStatement/BatchExecuteStatement operation. You need to enable BatchWriteItem only when inserting/updating binary/binary-set data. ExecuteStatement/BatchExecuteStatement doesn't support manipulating binary fields.

Whether to alyways use Consistent Reads or not when querying DynamoDb.

Data Type

bool

Default Value

false

Remarks

This parameter is not supported on global secondary indexes. If you scan or query using a secondary index, Constistent Reads will not be used even if the property is set to true.

Boolean determining if simple names should be used for tables and columns.

Data Type

bool

Default Value

false

Remarks

Amazon DynamoDB tables and columns can use special characters in names that are normally not allowed in standard databases. UseSimpleNames makes the Cloud easier to use with traditional database tools.

Setting UseSimpleNames to true will simplify the names of tables and columns returned. It will enforce a naming scheme such that only alphanumeric characters and the underscore are valid for the displayed table and column names. Any nonalphanumeric characters will be converted to an underscore.