From: Florian Weimer <fweimer@bfk.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: kakarukeys <kakarukeys@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: adding foreign key constraint locks up table
Date: Tue, 04 Jan 2011 13:52:24 +0000
Message-ID: <8239p8rd2f.fsf@mid.bfk.de> (raw)
In-Reply-To: <19238.1293548900@sss.pgh.pa.us>
References: <75218696-61be-4730-89f6-dd6058fa9eda@a28g2000prb.googlegroups.com>
<82ei926j3p.fsf@mid.bfk.de>
<19238.1293548900@sss.pgh.pa.us>
* Tom Lane:
>> Do you mean that the ALTER query and subsequent queries are shown as
>> "waiting" in pg_stat_activity? In this case, I'm also wondering why
>> this is inecessary.
>
> ALTER ADD FOREIGN KEY must lock both tables to add triggers to them.
But why is such a broad lock needed? If the table was created in the
current transaction and is empty, the contents of the foreign key
table should not matter.
--
Florian Weimer <fweimer@bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstraße 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99
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To: pgsql-performance@postgresql.org
Cc: fweimer@bfk.de, tgl@sss.pgh.pa.us, kakarukeys@gmail.com
Subject: Re: adding foreign key constraint locks up table
In-Reply-To: <8239p8rd2f.fsf@mid.bfk.de>
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