ttCommitBufferStats

This built-in procedure returns the number of commit buffer overflows and the high watermark for memory used by transaction reclaim records during transaction commit process.

The information provided by the results of this procedure call is useful information when you want to explicitly set the maximum size of commit buffer, using the CommitBufferSizeMax connection attribute or the ALTER SESSION SQL statement, described in Oracle TimesTen In-Memory Database SQL Reference. This procedure helps you choose the right size for the reclaim buffer, based on the number of overflows and the maximum memory used by the reclaim records.

If there are buffer overflows, you may consider increasing the commit buffer maximum size. If there are no overflows and the highest amount of memory usage is well under the commit buffer maximum size, you may consider decreasing the maximum size.

For more information on reclaim operations, including details about setting the commit buffer size, see Transaction Reclaim Operations in the Oracle TimesTen In-Memory Database Operations Guide.

Required Privilege

This procedure requires no privileges.

Usage in TimesTen Scaleout and TimesTen Classic

This procedure is supported in TimesTen Classic.

TimesTen Scaleout applications can call this built-in procedure.

In TimesTen Scaleout, this procedure returns a row for the element from which it was called. To see information about other elements, query the SYS.GV$COMMIT_BUFFER_STATS system table.

Related Views

This procedure has these related views.

SYS.GV$COMMIT_BUFFER_STATS

SYS.V$COMMIT_BUFFER_STATS

Syntax

ttCommitBufferStats()

Parameters

ttCommitBufferStats takes no parameters.

Result Set

ttCommitBufferStats returns these results:

Column	Type	Description
`overflows`	`TT_INTEGER NOT NULL`	Total number of commit buffer overflows.
`maxReached`	`TT_BIGINT NOT NULL`	The currently used maximum for the transaction commit buffer in bytes.

Examples

This shows the result for a session where there have been no commit buffer overflows and the transaction commit buffer is set to 500 MB.

Command> ALTER SESSION SET COMMIT_BUFFER_SIZE_MAX = 500;
Session altered.
Command> CALL ttCommitBufferStats();
< 0, 524288000 >
1 row found

For a session where there have been 10 commit buffer overflows and the transaction commit buffer is set to 2 MB, the output of this procedure is:

Command> ALTER SESSION SET COMMIT_BUFFER_SIZE_MAX = 2;
Session altered.
Command> CALL ttCommitBufferStats();
< 10, 2097152 >
1 row found

Note:

When you call the built-in procedure ttCommitBufferStatsReset, the commit buffer statistics are expressed in bytes. However, the ttConfiguration output and the value set by the connection attribute CommitBufferSizeMax are expressed in MB.