Adding a Connection to Cassandra

1. In the application console, navigate to the Connections page.
2. At the Add Connections panel, select the icon for the connection you want to add.
3. If the Cassandra icon is not available, click the Add More icon to download and install the Cassandra connector from the CData site.

For required properties, see the Settings tab.

For connection properties that are not typically required, see the Advanced tab.

Connecting to Cassandra

You can connect directly to Cassandra instances, as well as Cosmos DB and DataStax Astra DB via their Cassandra APIs.

Cassandra

Set the following to connect to a Cassandra instance:

• Server: Set this to the the host name or IP address of the server hosting the Cassandra database. You can specify the port at the end of this property or in Port.
• Port: Set this to the port on which the Cassandra database is hosted, if you haven't specified the port as part of the Server connection property.
• Database: Set this to the name of the Cassandra keyspace containing your tables.
• ConsistencyLevel: Set this to the number of the replicas that you want to enforce a response from before queries are considered a success.
• User: Set this to the username used to access your Cassandra database.
• Password: Set this to the password used to access your Cassandra database.

Cosmos DB

• Server: Set this to the Host value, the FQDN of the server provisioned for your account. You can specify the port at the end of this property or in Port.
• Port: Set this to the port on which your Cosmos DB instance is hosted, if you haven't specified the port as part of the Server connection property.
• Database: Set this to the database you want to read from and write to.
• ConsistencyLevel: Set this to the number of the replicas that you want to enforce a response from before queries are considered a success.
• User: Set this to your Cosmos DB account name.
• Password: Set this to the account key associated with the Cosmos DB account.

DataStax Astra DB

If you're using Astra DB as your Cassandra data store, specify the following values to connect:

• Server: Set this to the server in your BASE_ADDRESS value. You can also specify the port here or in Port.
• Port: Set this to the port on which your Astra DB instance is hosted, if you haven't specified the port as part of the Server connection property.
• Database: Set this to the database you want to read from and write to.
• ConsistencyLevel: Set this to the number of the replicas that you want to enforce a response from before queries are considered a success.
• User: Set this to your Astra DB username.
• Password: Set this to the password associated with your Astra DB username.

Secure Bundle Connection

• Server: Set this to your server name.
• Port: Set this to 29042.
• User: Set this to the Atra DB user.
• Password: Set this to Astra DB user password.
• SSLClientCert: Set this to the path to the identity.jks file.
• SSLClientCertType: Set this JKSFILE.
• SSLClientCertPassword: Set this to the password for the identity.jks file.
• SSLClientCertSubject: Set this to CERTIFICATE SUBJECT INFORMATION.
• UseSSL: Set this to "true".

See Secure connect bundle contents for a list of files that are included in a secure bundle.

Authenticating to Cassandra

You need to set AuthScheme to the value corresponding to the authenticator configured for your system. You specify the authenticator in the authenticator property in the cassandra.yaml file. This file is typically found in /etc/dse/cassandra or through the DSE Unified Authenticator on DSE Cassandra.

Basic

Set AuthScheme to Basic to authenticate with login credentials alone.

In the cassandra.yaml file, set the authenticator property to "PasswordAuthenticator".

DSE

Set the AuthScheme property to DSE to authenticate with login credentials and the DSE Unified Authenticator.

In the file, set the authenticator property to "com.datastax.bdp.cassandra.auth.DseAuthenticator".

Kerberos

Set the following to authenticating using Kerberos:

• AuthScheme: Set this to KERBEROS.
• KerberosKDC: Set this to the Kerberos Key Distribution Center (KDC) service used to authenticate the user.
• KerberosRealm: Set this to the Kerberos Realm used to authenticate the user.
• KerberosSPN: Set this to the service principal name (SPN) for the Kerberos Domain Controller.

• In the cassandra.yaml file, set the authenticator property to "com.datastax.bdp.cassandra.auth.DseAuthenticator".
• Modify the authentication_options section in the dse.yaml file, specifying the default_schema and other_schemas properties as "kerberos".
• Modify the kerberos_options section in the dse.yaml file, specifying the keytab, service_principle, http_principle and qop properties.

Please see Using Kerberos for more details on how to set connection properties in order to connect to Kerberos.

LDAP

Set the following to authenticate:

• AuthScheme: Set this to LDAP to authenticate an LDAP user.
• LDAPServer: Set this to the host name or IP address of the LDAP server.
• LDAPPassword: The password of the default LDAP user.

• In the cassandra.yaml file, set the authenticator property to "com.datastax.bdp.cassandra.auth.DseAuthenticator".
• Modify the authentication_options section in the dse.yaml file, specifying the default_schema and other_schemas properties as "ldap".
• Modify the ldap_options section in the dse.yaml file, specifying the server_host, server_port, search_dn, search_password, user_search_base, and user_search_filter properties.

Securing Cassandra Connections

You can set UseSSL to negotiate SSL/TLS encryption when you connect. By default, the Sync App 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.

Kerberos

To authenticate to Cassandra with Kerberos, set AuthScheme to KERBEROS.

Authenticating to Cassandra via Kerberos requires you to define authentication properties and to choose how Kerberos should retrieve authentication tickets.

Retrieve Kerberos Tickets

The Sync App provides three ways to retrieve the required Kerberos ticket, depending on whether or not the KRB5CCNAME and/or KerberosKeytabFile variables exist in your environment.

MIT Kerberos Credential Cache File

This option enables you to use the MIT Kerberos Ticket Manager or kinit command to get tickets. With this option there is no need to set the User or Password connection properties.

This option requires that KRB5CCNAME has been created in your system.

To enable ticket retrieval via MIT Cerberos Credential Cache Files:

1. Ensure that the KRB5CCNAME variable is present in your environment.
2. Set KRB5CCNAME to a path that points to your credential cache file. (For example, C:\krb_cache\krb5cc_0 or /tmp/krb5cc_0.) The credential cache file is created when you use the MIT Kerberos Ticket Manager to generate your ticket.
3. To obtain a ticket:
   1. Open the MIT Kerberos Ticket Manager application.
   2. Click Get Ticket.
   3. Enter your principal name and password.
   4. Click OK.

   If the ticket is successfully obtained, the ticket information appears in Kerberos Ticket Manager and is stored in the credential cache file.

The Sync App uses the cache file to obtain the Kerberos ticket to connect to Cassandra.

Note: If you would prefer not to edit KRB5CCNAME, you can use the KerberosTicketCache property to set the file path manually. After this is set, the Sync App uses the specified cache file to obtain the Kerberos ticket to connect to Cassandra.

Keytab File

If your environment lacks the KRB5CCNAME environment variable, you can retrieve a Kerberos ticket using a Keytab File.

To use this method, 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.

User and Password

If your environment lacks the KRB5CCNAME environment variable and the KerberosKeytabFile property has not been set, you can retrieve a ticket using a user and password combination.

To use this method, set the User and Password properties to the user/password combination that you use to authenticate with Cassandra.

Enabling Cross-Realm Authentication

To enable this kind of cross-realm authentication, 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.

Fine Tuning Data Access

You can use the following properties to gain greater control over Cassandra API features and the strategies the Sync App uses to surface them:

• AllowFiltering: Set this property to allow the server to process slow-performing searches.
• UseJsonFormat: Set this property to use CQL literals instead of JSON.
• QueryPassthrough: This property enables you to use native CQL statements instead of SQL.
• RowScanDepth: This property determines the number of rows that will be scanned to detect column data types when generating table metadata.

  This property applies if you are working with the dynamic schemas generated from Automatic Schema Discovery or if you are using QueryPassthrough.

Cassandra is a NoSQL database that provides high performance, availability, and scalability. However, these capabilities are not necessarily incompatible with a standards-compliant query language like SQL-92. The Sync App models Cassandra tables into relational tables and translates SQL queries into calls to the Cassandra API, the CQL (Cassandra Query Language) binary protocol.

The equivalent of a table in Cassandra is a column family. Column families contain columns of related data. Like other NoSQL databases, Cassandra allows complex types of fields such as set, list, and map. A column family is a nested map data structure. This can be represented as a JSON object.

The Sync App offers two ways to model Cassandra objects. The Automatic Schema Discovery scheme automatically finds the data types in a Cassandra object by scanning a configured number of rows of the object. You can use RowScanDepth, FlattenArrays, and FlattenObjects to control the relational representation of the tables in Cassandra.

The Sync App automatically infers a relational schema by inspecting a series of Cassandra documents in a collection. You can use the RowScanDepth property to define the number of documents the Sync App 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.

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.

The Sync App can return JSON structures as column values. The Sync App 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;

JSON

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

SELECT JSON(*) 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 }

Data Type Mappings

The Sync App maps types from the data source to the corresponding data type available in the schema. The table below documents these mappings.

Note that string columns can map to different data types depending on their length.

This section details a selection of advanced features of the Cassandra Sync App.

User Defined Views

The Sync App 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.

SSL Configuration

Use SSL Configuration to adjust how Sync App handles TLS/SSL certificate negotiations. You can choose from various certificate formats; see the SSLServerCert property under "Connection String Options" for more information.

Firewall and Proxy

Configure the Sync App for compliance with Firewall and Proxy, including Windows proxies. You can also set up tunnel connections.

Query Processing

The Sync App offloads as much of the SELECT statement processing as possible to Cassandra and then processes the rest of the query in memory (client-side).

See Query Processing for more information.

Logging

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.

Customizing the SSL Configuration

By default, the Sync App 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.

Client SSL Certificates

The Cassandra Sync App also supports setting client certificates. Set the following to connect using a client certificate.

• SSLClientCert: The name of the certificate store for the client certificate.
• 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.

Connecting Through a Firewall or Proxy

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 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.

Authentication

Kerberos

SSL

SSH

Firewall

Logging

Schema

Miscellaneous

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

The scheme used for authentication. Accepted entries are Basic, DSE, Kerberos, and LDAP.

Remarks

Set this property to authenticate to open-source or DataStax Enterprise (DSE) Cassandra instances.

Together with Password and User, this field is used to authenticate against the server. Basic is the default option. Use the following options to select your authentication scheme:

• Basic: Set this to authenticate with login credentials and Cassandra's built-in authentication.
• DSE: Set this to authenticate with login credentials and the DSE Unified Authenticator.
• Kerberos: Set this to use Kerberos to authenticate.
• LDAP: Set this to use LDAP to authenticate.

The host name or IP address of the server hosting the Cassandra database.

Remarks

The host name or IP address of the server hosting the Cassandra database. To connect to a distributed system, you can set Server to a comma-separated list of servers and ports, separated by colons. You will also need to set ConsistencyLevel.

Note that you must specify all of the servers required by your selected consistency level.

The port for the Cassandra database.

Remarks

The port for the Cassandra database.

The host name or IP address of the LDAP server.

Remarks

The host name or IP address of the LDAP server.

The Cassandra user account used to authenticate.

Remarks

Together with Password, this field is used to authenticate against the Cassandra server.

The password used to authenticate the user.

Remarks

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

The port for the LDAP server.

Remarks

The port for the LDAP server.

The name of the Cassandra keyspace.

Remarks

The name of the Cassandra keyspace containing the tables.

The default LDAP user used to connect to and communicate with the server, it must be set if the LDAP server do not allow anonymous bind.

Remarks

Specify the default LDAP user in case the LDAP server do not allow anonymous login.

The password of the default LDAP user. It must be set if the LDAP server do not allow anonymous bind.

Remarks

Specify the password of the default LDAP user.

The search base for your LDAPServer, used to look up users.

Remarks

The search base for your LDAPServer, used to look up users.

The search filter for looking up usernames in LDAP. The default setting is (uid=), When using Active Directory set the filter to (sAMAccountName=).

Remarks

The search filter for looking up usernames in LDAP. The default setting is (uid=).

This field sets whether SSL is enabled.

Remarks

This field sets whether the Sync App will attempt to negotiate TLS/SSL connections to the server. By default, the Sync App checks the server's certificate against the system's trusted certificate store. To specify another certificate, set SSLServerCert.

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

The Kerberos Key Distribution Center (KDC) service used to authenticate the user.

Remarks

The Kerberos properties are used when using SPNEGO or Windows Authentication. The Sync App 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 Sync App will attempt to detect these properties automatically from the following locations:

• KRB5 Config File (krb5.ini/krb5.conf): If the KRB5_CONFIG environment variable is set and the file exists, the Sync App will obtain the KDC from the specified file. Otherwise, it will attempt to read from the default MIT location based on the OS: C:\ProgramData\MIT\Kerberos5\krb5.ini (Windows) or /etc/krb5.conf (Linux).
• Domain Name and Host: If the Kerberos Realm and Kerberos KDC could not be inferred from another location, the Sync App will infer them from the configured domain name and host.

The Kerberos Realm used to authenticate the user.

Remarks

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 Sync App will attempt to detect these properties automatically from the following locations:

• KRB5 Config File (krb5.ini/krb5.conf): If the KRB5_CONFIG environment variable is set and the file exists, the Sync App will obtain the default realm from the specified file. Otherwise, it will attempt to read from the default MIT location based on the OS: C:\ProgramData\MIT\Kerberos5\krb5.ini (Windows) or /etc/krb5.conf (Linux)
• Domain Name and Host: If the Kerberos Realm and Kerberos KDC could not be inferred from another location, the Sync App will infer them from the user-configured domain name and host. This might work in some Windows environments.

The service principal name (SPN) for the Kerberos Domain Controller.

Remarks

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.

Remarks

The Keytab file containing your pairs of Kerberos principals and encrypted keys.

The Kerberos realm of the service.

Remarks

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.

Remarks

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.

Remarks

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.

The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL).

Remarks

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:

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.

Remarks

This property can take one of the following values:

The password for the TLS/SSL client certificate.

Remarks

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.

Remarks

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.

If a field value contains a comma, it must be quoted.

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

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

The authentication method used when establishing an SSH Tunnel to the service.

Remarks

• None: No authentication is performed. The current User value is ignored, and the connection is logged in as anonymous.
• Password: The Sync App uses the values of User and Password to authenticate the user.
• Public_Key: The Sync App uses the values of User and SSHClientCert to authenticate the user. SSHClientCert must have a private key available for this authentication method to succeed.

A certificate to be used for authenticating the SSHUser.

Remarks

SSHClientCert must contain a valid private key in order to use public key authentication. A public key is optional, if one is not included then the Sync App generates it from the private key. The Sync App sends the public key to the server and the connection is allowed if the user has authorized the public key.

The SSHClientCertType field specifies the type of the key store specified by SSHClientCert. If the store is password protected, specify the password in SSHClientCertPassword.

Some types of key stores are containers which may include multiple keys. By default the Sync App will select the first key in the store, but you can specify a specific key using SSHClientCertSubject.

The password of the SSHClientCert key if it has one.

Remarks

This property is only used when authenticating to SFTP servers with SSHAuthMode set to PublicKey and SSHClientCert set to a private key.

The subject of the SSH client certificate.

Remarks

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 instance "CN=www.server.com, OU=test, C=US, [email protected]". Common fields and their meanings are displayed below.

If a field value contains a comma it must be quoted.

The type of SSHClientCert private key.

Remarks

This property can take one of the following values:

The SSH server.

Remarks

The SSH server.

The SSH port.

Remarks

The SSH port.

The SSH user.

Remarks

The SSH user.

The SSH password.

Remarks

The SSH password.

The SSH server fingerprint.

Remarks

The SSH server fingerprint.

Whether to tunnel the Cassandra connection over SSH. Use SSH.

Remarks

By default the Sync App will attempt to connect directly to Cassandra. When this option is enabled, the Sync App will instead establish an SSH connection with the SSHServer and tunnel the connection to Cassandra through it.

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

The protocol used by a proxy-based firewall.

Remarks

This property specifies the protocol that the Sync App will use to tunnel traffic through the FirewallServer proxy.

The name or IP address of a proxy-based firewall.

Remarks

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.

The TCP port for a proxy-based firewall.

Remarks

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.

Remarks

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.

Remarks

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

Core modules to be included in the log file.

Remarks

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.

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

A path to the directory that contains the schema files defining tables, views, and stored procedures.

Remarks

The path to a directory which contains the schema files for the Sync App (.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\\Cassandra 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.

Remarks

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.

Remarks

Listing the tables from some databases can be expensive. Providing a list of tables in the connection string improves the performance of the Sync App.

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.

Remarks

Listing the views from some databases can be expensive. Providing a list of views in the connection string improves the performance of the Sync App.

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

Whether or not to support aggregations in the Cassandra server. Note that in queries to the provider, you must use single quotes to define strings.

Remarks

When true, slow-performing queries are processed on the server.

Remarks

Cassandra by default does not allow filtering for queries that it predicts will have performance problems. These queries include filtering on a column that is not the primary key.

You can override the default behavior and rely on the server to process these queries by setting AllowFiltering to true.

Enable case sensitivity to the CQL sending to the server, if set to True, the identifiers in the CQL will be enclosed in double quotation marks.

Remarks

By default, SQL is case-insensitive. However, Cassandra supports case-sensitive table and column names. Setting this property to True will enable you to retrieve tables and columns based on their case-sensitive names.

The consistency level determines how many of the replicas of the data you are interacting with need to respond for the query to be considered a success.

Remarks

The consistency level determines how many of the replicas of the data you are interacting with need to respond for the query to be considered a success. You need to specify the appropriate replicas in the Server property.

Below are the possible values:

• ANY: At least one replica must return success in a write operation. This property guarantees that a write never fails; this consistency level delivers the lowest consistency and highest availability.
• ALL: All replicas must respond. This property provides the highest consistency and the lowest availability.
• ONE: At least one replica must respond. This is the default and suitable for most users, who do not typically require high consistency.
• TWO: At least two replicas must respond.
• THREE: At least three replicas must respond.
• QUORUM: A quorum of nodes must respond. The QUORUM properties provide high consistency with some failure tolerance.
• EACH_QUORUM: A quorum of nodes must respond where a quorum is calculated for each data center. This setting maintains consistency in each data center.
• SERIAL: A quorum of replicas performs a consensus algorithm to allow lightweight transactions.
• LOCAL_ONE: At least one replica in the local data center must respond.
• LOCAL_SERIAL: The consensus algorithm is calculated for the local data center.
• LOCAL_QUORUM: A quorum of nodes must respond where the quorum is calculated for the local data center.

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.

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.

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 }
]

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

Remarks

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

Use unset instead of NULL in CQL query when performing INSERT operations.

Remarks

In Cassandra 2.2 and above, when executing an INSERT query, a parameter value can be set to unset. Cassandra does not consider unset field values which helps to avoid tombstones.

When NULL values are inserted, it is possible to reach the tombstone threshold limits which causes an exception to be thrown when querying the data. Setting this property to true and submitting unset values avoids these tombstones from being created.

Note: This option is only available on INSERT operations as Cassandra does not support changing existing values to unset.

These hidden properties are used only in specific use cases.

Remarks

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.

Integration and Formatting

The maximum number of results to return per page from Cassandra.

Remarks

The Pagesize property affects the maximum number of results to return per page from Cassandra. 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.

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 option passes the query to the Cassandra server as is.

Remarks

When this is set, queries are passed through directly to Cassandra.

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

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

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 Sync App throws an exception.

Whether to submit and return the JSON encoding for CQL data types.

Remarks

Cassandra 2.2 introduced a CQL extension that allows you to JSON-encode CQL data types. By default, you use the JSON syntax to manipulate data and SELECT statements return JSON through the Sync App. Set this property to false to use CQL literals to interact with Cassandra data.

The syntax for CQL literals has several differences from JSON. For example:

• CQL strings are defined in single quotes, while JSON strings are defined in double quotes.
• CQL sets, tuples, and lists are JSON-encoded as arrays.
• User-defined types and CQL uuid types are JSON-encoded as objects.

INSERT INTO users (user_id, emails) VALUES (@user_id, @emails)

INSERT INTO users (user_id, emails) VALUES (@user_id, @emails)

Note that in queries to the Sync App, you must use single quotes to define strings.

A filepath pointing to the JSON configuration file containing your custom views.

Remarks

User Defined Views are defined in a JSON-formatted configuration file called UserDefinedViews.json. The Sync App 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 Sync App.

This User Defined View configuration file is formatted as follows:

• Each root element defines the name of a view.
• Each root element contains a child element, called query, which contains the custom SQL query for the view.

For example:

{
	"MyView": {
		"query": "SELECT * FROM \"CData\".\"Sample\".Products WHERE MyColumn = 'value'"
	},
	"MyView2": {
		"query": "SELECT * FROM MyTable WHERE Id IN (1,2,3)"
	}
}

"UserDefinedViews", C:\Users\yourusername\Desktop\tmp\UserDefinedViews.json

Map Cassandra VARINT to String value.

Remarks

Map Cassandra VARINT to String value.