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Topic: standby 12.1 library cache: mutex X

oracle 12.1.0.2.170418
Started up small  requests on
Time in some days  sessions with user queries on library cache roll over: mutex X
Up to that the basis ceases to move
Stop  helps
Then it is severe
alter system flush shared_pool;
alter system flush buffer_cache;
We include  and as though anything and was not
On 11  saw bugs on this subject, on 12 anything interesting did not find
What ?

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Re: standby 12.1 library cache: mutex X

Specific council is not present, but try to fulfill to begin with

select sql_id, count (*) from V$SQL_SHARED_CURSOR group by sql_id order by 2 desc

Also will look at what amount in a top.
I once had a similar situation with waiting library cache: mutex X which tightly laid down one of jobs on queue handlings streams.

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Re: standby 12.1 library cache: mutex X

The request at the moment of a problem showed in a top more than 2 million divided cursors on one request. Makeshift was to throw out periodically request from a pool

begin
sys.dbms_shared_pool.purge (' 0000003E0EF3C010, 3523218400 ', ' c ');
end;

Here   on procedure dbms_shared_pool.purge.

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Re: standby 12.1 library cache: mutex X

AlexVin;
Troubleshooting ' library cache: mutex X ' Waits. (Doc ID 1357946.1) - read already?

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Re: standby 12.1 library cache: mutex X

AlexVin;
And by search in a forum walk
1 , 2 , 3 and further

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Re: standby 12.1 library cache: mutex X

And here what in v$sql_shared_cursor for such request anything is not present - for  it normally?

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Re: standby 12.1 library cache: mutex X

AlexVin;