Re: DROP OWNED BY fails with #53200: ERROR: out of shared memory

On 1/10/22 13:08, David G. Johnston wrote:
> On Mon, Jan 10, 2022 at 12:09 PM Dominique Devienne <ddevienne@gmail.com 
> <mailto:ddevienne@gmail.com>> wrote:
> 
>     Given |max_locks_per_transaction| * (max_connections
>     <https://www.postgresql.org/docs/current/runtime-config-connection.html#GUC-MAX-CONNECTIONS> +
>     max_prepared_transactions
>     <https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAX-PREPARED-TRANSACTIONS>)
>     from
>     https://www.postgresql.org/docs/current/runtime-config-locks.html
>     <https://www.postgresql.org/docs/current/runtime-config-locks.html>,
>     and max_conn being 100, that's not many locks.
> 
>     Tom wrote "relation" for the number of locks necessary for DROP
>     OWNED BY.
>     What does it mean in this context? relation = table?
> 
> 
> 
> I'm confused here a bit as well.  The items being talked about are 
> tables and indexes, both of which manifest as files on the filesystem.  
> But not all relations do (e.g., views).  But if this isn't tied to the 
> filesystem then I would expect that other object types, especially 
> functions, would require locking as well, but those are decidedly not 
> relations.

Pretty sure this is related to:

https://www.postgresql.org/docs/current/explicit-locking.html

In other words to locks on data access.


> 
>         How do I determine the current value, and change it?
> 
> 
> https://www.postgresql.org/docs/current/runtime-config.html 
> <https://www.postgresql.org/docs/current/runtime-config.html>
> (you already used the SHOW command to determine the current value)
> 
> David J.
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com