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10053

Creating Optimizer Trace Files

Many Oracle DBA’s are probably familiar with what Optimizer trace files are and likely know how to create them. When I say “Optimizer trace” more than likely you think of event 10053, right? SQL code like this probably is familiar then:

alter session set tracefile_identifier='MY_10053';
alter session set events '10053 trace name context forever';
select /* hard parse comment */ * from emp where ename = 'SCOTT';
alter session set events '10053 trace name context off';

In 11g, a new diagnostic events infrastructure was implemented and there are various levels of debug output that you can control for sql compilation. ORADEBUG shows us the hierarchy.