Re: shared pool waits

  • From: Mladen Gogala <gogala.mladen@xxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Tue, 21 Sep 2021 10:06:55 -0400

On 9/20/21 15:25, Pap wrote:

Hi , We have a customer application in which we see high wait events like 'cursor:mutex ' and 'library cache lock' for a select query occasionally and thus a specific functionality impacted. This select query(which is part of a plsql procedure) is quick query which runs ~5 million times/hr. But even though number of execution is same mostly throughout the day, it still went through these odd wait events making the per execution time went higher for around ~15 minutes duration causing slowness. And during this period, the ASH shows fro this query,  the value of column in_hard_parse as 'N' but in_parse as 'Y' and 'N' both. And we saw we were having stats gather running on that base object during same time. We have no_invalidate set as 'FALSE" as table stats preference, So wanted to understand from experts, can it be really because of 'parsing' issue and we should delete this no_invalidate preference so that it can inherit the default global preference i.e no_invalidate=>auto? The database version is 19C.

How about pinning the procedure in the SGA? That seems to be the purpose of DBMS_SHARED_POOL.KEEP procedure.

Mladen Gogala
Database Consultant
Tel: (347) 321-1217


Other related posts: