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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fabrice Chapuis <fabrice636861@gmail.com>
cc: pgsql-general@postgresql.org
Subject: Re: infinite loop in an update statement
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Comments: In-reply-to Fabrice Chapuis <fabrice636861@gmail.com>
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Fabrice Chapuis <fabrice636861@gmail.com> writes:
> why this update does not return instantly?

> UPDATE table_a a
>  SET col1 = (SELECT MIN(b.col1)
>                     FROM table_b b
>                     WHERE b.col2 = a.col2)

Maybe query is waiting for a lock on one of those tables?

			regards, tom lane