Connection Attributes for Data Manager DSNs or Server DSNs

On Linux and UNIX, you specify connection attributes in the odbc.ini file. Connection attributes that do not appear in the odbc.ini file assume their default value.

Common types of connection attributes:

Note:

For a complete description of all attributes, see List of Connection Attributes in Oracle TimesTen In-Memory Database Reference.

  • Data Store attributes are associated with a database when it is created and cannot be modified by subsequent connections. They can only be changed by destroying and re-creating the database.

    The following are the most commonly used data store attributes:

    • DataStore: Directory name and file name prefix of the database.

    • LogDir: Directory name of the database transaction log files. Placing the transaction log files and checkpoint files on different file systems can improve system performance.

    • DatabaseCharacterSet: Required character set specification that defines the storage encoding.

  • First connection attributes are used when the TimesTen database is loaded into memory. Only the instance administrator can load a database with first connection attribute settings. By default, TimesTen loads an idle database, which is a database with no connections, into memory when a first connection is made to it. These attributes persist for all subsequent connections until the last connection to the database is closed. First connection attributes can be modified only when the TimesTen database is unloaded and then the instance administrator reconnects with different values for the first connection attributes.

    The following are the most commonly used first connection attributes:

    • PermSize: Configures the allocated size of the database's permanent memory region. The permanent memory region contains persistent database objects. TimesTen only writes the permanent memory region to the file system during a checkpoint operation.

    • TempSize: Configures the allocated size of the database's temporary memory region. The temporary memory region contains transient data generated when running statements.

      Note:

      Your system must have sufficient main memory to accommodate the entire database. For more details on setting region sizes, see Specifying the Memory Region Sizes of a Database.

  • General connection attributes are set by each connection and persist for the duration of the connection. Each concurrent connection can have different values.

    The following are the most commonly used general connection attributes:

    Note:

    If you provide connection attributes in the connection string, this overrides the connection attributes set in the DSN. See Connecting to a Database Using a Connection String.

    • UID: Specifies the user name to be used for the connection to the database, whether using a direct or client/server connection. To connect as the instance administrator or as an external user, you do not need to specify a user name. When you do not specify a user name, TimesTen assumes that the UID is the user name identified by the operating system.

    • PWD: Specifies the password that corresponds with the specified UID. For internal users, if you do not set the PWD attribute in the odbc.ini file for the specified DSN or in the connection string, TimesTen prompts for the password. For external users, you do not provide the password as it is verified by the operating system.

      When you initiate a client/server connection, the password sent for the connection is encrypted by the client/server protocol.

    • PWDCrypt: Specifies the encrypted password that corresponds with the specified UID.

    • PwdWallet: TimesTen enables you to store user names and associated passwords in an Oracle Wallet. This is the most secure and preferred method of providing credentials for connecting to a TimesTen database. The PwdWallet connection attribute is the path to the location of the wallet, from which TimesTen retrieves the password for the specified user name.

    • Note:

      For more information, see UID and PWD, PWDCrypt, and PwdWallet in Oracle TimesTen In-Memory Database Reference. See Authentication in TimesTen in Oracle TimesTen In-Memory Database Security Guide.

  • Cache attributes enable you to enter the Oracle Service Identifier for the Oracle database instance from which data is loaded into TimesTen.

Note:

See Working with the TimesTen Client and Server for a description of the connection attributes that can be used with the TimesTen client ODBC driver.