Re: Question on concurrency waits

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