Re: Alter command getting stuck on a table

Hello,

Thank you all,
that helped me to get rid of the issues, using pg_locks and
pg_stat_activity I was able to find out concurrent session which was not
allowing to hold exclusive lock.

Thanks

On Wed, Jan 8, 2020 at 12:34 AM Jerry Sievers <gsievers19(at)comcast(dot)net>
wrote:

> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>
> > Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at> writes:
> >
> >> On Tue, 2020-01-07 at 14:58 +0530, Shrikant Bhende wrote:
> >>> I am trying to add a column to a table but it's not working, I have
> also tried
> >>> reindex and drop on the same table but those commands are also getting
> stuck.
> >
> >> There is a concurrent session which has an open transaction which
> >> holds some lock on the table in question.
> >
> > Yes, that looks like the cause. The pg_locks view could help you
> > find the culprit session.
>
> Yeah, and IMO the pg_blocking_pids($blocked-guys-pid) function is pretty
> snazzy too :-)
>
>
> > regards, tom lane
> >
> >
> >
>
> --
> Jerry Sievers
> Postgres DBA/Development Consulting
> e: postgres(dot)consulting(at)comcast(dot)net
>