Adjusting STATSPACK Collection levels

Oracle Tips by Burleson Consulting
Don Burleson

STATSPACK has two types of collection options, level and threshold. The level parameter controls the type of data collected from Oracle, while the threshold parameter acts as a filter for the collection of SQL statements into the stats$sql_summary table.

Snapshot Levels

There are three snapshot levels used in STATSPACK, and level 5 is the default:

Level 0: General Performance Statistics This level collects general performance statistics, such as wait statistics, system events, system statistics, rollback segment data, row cache, SGA, background events, session events, lock statistics, buffer pool statistics, and parent latch statistics.

Level 5: Add SQL Statements This level includes all level 0 statistics plus SQL statements into the stats$sql_summary table.

Level 7 (Oracle9i r2 and above only) - This level captures segment level statistics, including logical and physical reads, row lock, itl and buffer busy waits, along with all data captured by lower levels.

Level 10: Add Child Latch Statistics The level 10 snapshot includes everything in the level 5 statistics plus the addition of child latches into the stats$latch_children table. You rarely, if ever, need this level of detail, and you should only do a level 10 snapshot when directed by Oracle technical support.

To check your STATSPACK collection level:

SELECT * FROM stats$level_description ORDER BY snap_level;

Change the STATSPACK collection level to level 5 like this:

exec statspack.snap(i_snap_level => 5, i_modify_parameter => 'true');

For full details on setting STATSPACK collection thresholds and all about STATSPACK analysis, the book "Oracle Tuning: The Definitive Reference" is highly recommended.

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