From: John Fabiani <johnf@jfcomputer.com>
To: pgsql-sql@postgresql.org
Subject: foreign key is it a real key
Date: Mon, 13 Feb 2012 07:46:31 -0800
Message-ID: <5075215.HTHcEtzjPG@linux-12> (raw)
Hi,
I have read a few articles and I'm not sure if it's me or the authors but I do
not believe my question was answered.
If I have table that has a PK and a FK - will the planner use the FK just same
as it would use the PK? IOW's is a FK also an index used by the planner?
I have a lagacy table that contains a FK constraint (vendor_id -->
vendor_info). I believe I need an index to improve the performance of a query
because I'm using the column as part of my join. Explain does not appear to
use it as an index (instead of a seq scan it uses a hash join). But the table
all ready has a FK key contraint on the column.
Thanks in advance,
Johnf
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To: pgsql-sql@postgresql.org
Cc: johnf@jfcomputer.com
Subject: Re: foreign key is it a real key
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