Oracle: DBMS_STATS Gather Statistics of Schema, Tables, Indexes

Oracle: DBMS_STATS Gather Statistics of Schema, Tables, Indexes

DBMS_STATS package, which lets you collect statistics in parallel, collect global statistics for partitioned objects, and fine tune your statistics collection in other ways. This package is concerned with optimizer statistics only.
dbms_stats is essential to good SQL performance, and it should always be used before adjusting any of the Oracle optimizer initialization parameters.

Syntax:

exec DBMS_STATS.GATHER_SCHEMA_STATS(ownname,estimate_percent, block_sample , method_opt,degree,granularity,cascade,stattab, statid,options,statown ,no_invalidate, gather_temp,gather_fixed);

Code examples:

exec dbms_stats.gather_schema_stats('SCOTT',DBMS_STATS.AUTO_SAMPLE_SIZE);

exec dbms_stats.gather_schema_stats(ownname=>'SCOTT', estimate_percent=>DBMS_STATS.AUTO_SAMPLE_SIZE);

exec dbms_stats.gather_schema_stats(ownname => 'SCOTT', estimate_percent => 25);

exec dbms_stats.gather_table_stats('SCOTT', 'EMPLOYEES');

exec dbms_stats.gather_index_stats('SCOTT', 'EMPLOYEES_PK');

exec dbms_stats.delete_schema_stats('SCOTT');