Re: Question on concurrency waits
Date: Wed, 27 Oct 2021 08:03:06 +0100
Message-ID: <CACj1VR40ERDD3tbKU7PawNh6km=8LVLOJOUy_epsj8wVArhhfg_at_mail.gmail.com>
Your second priority is upgrading.
On Wed, 27 Oct 2021 at 00:25, Mladen Gogala <gogala.mladen_at_gmail.com> wrote:
>
> On 10/25/21 06:30, Pap wrote:
> > My mistake, one correction:- the cache_id for all those 'row cache
> > lock' is pointing to dc_users.
>
>
> Once upon a time, dc_ parameters were set in the init.ora. The "dc_"
> comes from "dictionary cache". Oracle instance had a fixed size
> dictionary for each type of objects: tables, views, indexes, sequences,
> users and some other stuff, too. Today, those caches are dynamic and
> extensible. However, if two processes attempt to manipulate the same
> cache entry, like the same username, one will have to wait, as you have
> just discovered. My favorite situation with dc_rowcache waits includes
> ordered sequences and RAC. That's when the story gets really, really
> interesting.
>
>
> --
> Mladen Gogala
> Database Consultant
> Tel: (347) 321-1217
> https://dbwhisperer.wordpress.com
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Oct 27 2021 - 09:03:06 CEST