Re: pg_am access in simple transaction?

On 11/25/2016 04:40 AM, pinker wrote:
> Hi,
> I'm doing simple tests with lsof on data catalog with bash script:
>
> #!/bin/bash
> for i in {0..2000}
> do
>     psql -U postgres -c '*BEGIN; select pg_sleep(30); COMMIT*'&
> done
>
> and i measure number of open files and what files are affected by specific
> command.
> Lsof has shown me that the only file that was open during this test was:
> data/base/13328/2601, which is pg_catalog table pg_am.
>
> Why postgres opens a table that stores information about relation (index)
> access methods, while none index evidently is in use?

I can not replicate using 50 clients instead of 2000. I suspect either
has to do with the extreme number of clients or it is an artifact of
from some other process.

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> --
> View this message in context: http://postgresql.nabble.com/pg-am-access-in-simple-transaction-tp5931974.html
> Sent from the PostgreSQL - general mailing list archive at Nabble.com.
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com