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SAP Sybase SQL Anywhere 16.0 » Context-Sensitive Help » ODBC Configuration window help » SQL Anywhere ODBC driver

 

ODBC Configuration for SQL Anywhere window: ODBC tab

This tab appears only when you are creating or modifying ODBC data sources.

  • Data source name   Type a name to identify this ODBC data source. You can use any descriptive name for the data source (spaces are allowed) but it is recommended that you keep the name short, as you may need to enter it in connection strings. See DataSourceName (DSN) connection parameter.

  • Description   You can provide a description of the data source. This description may help you or your end users to identify this data source from among their list of available data sources. This is an optional field.

  • Isolation level   Type a numerical value to specify the initial isolation level for this data source:

    • 0   This is also called the read uncommitted isolation level. It provides the maximum level of concurrency, but dirty reads, non-repeatable reads, and phantom rows may be observed in result sets. This is the default isolation level.

    • 1   This is also called the read committed level. This provides less concurrency than level 0, but eliminates some of the inconsistencies in result sets at level 0. Non-repeatable rows and phantom rows may occur, but dirty reads are prevented.

    • 2   This is also called the repeatable read level. Phantom rows may occur. Dirty reads and non-repeatable rows are prevented.

    • 3   This is also called the serializable level. This provides the least concurrency, and is the strictest isolation level. Dirty reads, non-repeatable reads, and phantom rows are prevented.

    • snapshot   This isolation level uses a snapshot of committed data from the time the first row is read, inserted, updated, or deleted by the transaction.

    • statement-snapshot   This isolation level uses a snapshot of committed data from the time the first row is read by the statement. Each statement within the transaction sees a snapshot of data from a different time.

    • readonly-statement-snapshot   For read-only statements, this isolation level uses a snapshot of committed data from the time when the first row is read. Each statement within the transaction sees a snapshot of data from a different time. For INSERT, UPDATE, and DELETE statements, use the isolation level specified by the updatable_statement_isolation option (can be one of 0 (the default), 1, 2, or 3). See updatable_statement_isolation option.

    See Guidelines for choosing isolation levels.

  • Microsoft applications (Keys in SQLStatistics)   Select this option if you want the SQLStatistics function to return foreign keys. The ODBC specification states that SQLStatistics should not return primary and foreign keys; however, some applications (such as Microsoft Visual Basic and Microsoft Access) assume that primary and foreign keys are returned by SQLStatistics.

  • Delphi applications   Select this option if you use the Embarcadero Delphi application development tool to create applications that produce your data source.

    When this option is selected, one bookmark value is assigned to each row instead of the two that are otherwise assigned (one for fetching forward and a different one for fetching backward).

    Delphi cannot handle multiple bookmark values for a row. If the option is cleared, scrollable cursor performance can suffer since scrolling must always take place from the beginning of the cursor to the row requested to get the correct bookmark value.

  • Suppress fetch warnings   Select this option to suppress warning messages that are returned from the database server on a fetch.

    Versions 8.0 and later of the database server return a wider range of fetch warnings than earlier versions of the software. For applications that are deployed with an earlier version of SQL Anywhere software, you can select this option to ensure that fetch warnings are handled properly.

  • Prevent driver not capable errors   The SQL Anywhere ODBC driver returns a Driver not capable error because it does not support qualifiers. Some ODBC applications do not handle this error properly. Select this option to prevent this error code from being returned, allowing these applications to work.

  • Delay AutoCommit until statement close   Select this option to delay the commit operation until a statement closes.

  • Describe Cursor Behavior   Choose how often you want a cursor to be redescribed when a procedure is executed. The default setting is If Required.

    • Never   Select this option if you know that your cursors do not have to be redescribed. Redescribing cursors is expensive and can decrease performance.

    • If required   When you select this option, the ODBC driver determines whether a cursor must be redescribed. The presence of a RESULT clause in your procedure prevents ODBC applications from redescribing the result set after a cursor is opened. This is the default.

    • Always   The cursor is redescribed each time it is opened. If you use Transact-SQL procedures or procedures that return multiple result sets, you must redescribe the cursor each time it is opened.

  • Test Connection   Tests whether the information provided results in a proper connection. For the test to work, a user ID and password must be specified on the Login tab.

 See also