Re: ALTER TABLE ADD COLUMN takes forever

On Mon, 2021-03-29 at 22:48 +0530, Devendra Yadav wrote:
> > I am running a query on a table - ALTER TABLE mytable ADD COLUMN deposited DOUBLE PRECISION DEFAULT 0.0;
> > > 
> > > this query just runs forever.
> > 
> > Then either you are using a PostgreSQL version older than v11, or there
> > is an open transaction that used the table and blocks you.
>
> We are using PostgreSQL v12.1
> There are no open transactions as the table is not blocked by any pid. However when i check pg_locks it say
granted=false
> but nothing blocking it. Bit strange!!

As I replied in the other thread you started, you are probably blocked
by a prepared transaction.

Yours,
Laurenz Albe
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