Re: SELECT from record-returning function causes function code to be executed multiple times

From: David Johnston <polobo(at)yahoo(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: SELECT from record-returning function causes function code to be executed multiple times
Date: 2013-12-15 22:09:11
Message-ID: 1387145351920-5783497.post@n5.nabble.com
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dbaston wrote
> I'm wondering if this is expected behavior?

Yes.

The proper way to handle this is by putting the SRF in the FROM clause.

If you must have it in the select clause you should do this:

WITH srf_call (
SELECT srf_function() AS srf_result
)
SELECT (srf_call.srf_result).* FROM srf_call;

Note that if you are using 9.3 you likely can make use of the new LATERAL
construct to leave the SRF call in the FROM clause while still pulling
parameter values from the same level in the query (which is the main reason
for moving the SRF to the select-list).

David J.

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