Hi,
pragmatically I used to solve these problems (in my opinion oracle bugs) by
creating a scheduler job to detect and remove the SQLs, that cause such
problems, from the shared pool (using dbms_shared_pool.purge).
Since one can not change the vendor's code.
Best regards
Ahmed
-----Original-Nachricht-----
Betreff: shared pool waits
Datum: 2021-09-20T21:25:36+0200
Von: "Pap" <oracle.developer35@xxxxxxxxx>
An: "Oracle L" <oracle-l@xxxxxxxxxxxxx>
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.
