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.