Re: Understanding EXPLAIN ANALYZE output

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Michael Fuhr <mike(at)fuhr(dot)org>
Cc: David Fetter <david(at)fetter(dot)org>, "Ed L(dot)" <pgsql(at)bluepolka(dot)net>, Martijn van Oosterhout <kleptog(at)svana(dot)org>, pgsql-general(at)postgresql(dot)org
Subject: Re: Understanding EXPLAIN ANALYZE output
Date: 2005-02-10 04:36:22
Message-ID: 22773.1108010182@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Michael Fuhr <mike(at)fuhr(dot)org> writes:
> I started looking at this earlier. Is it even possible to get
> EXPLAIN output via SPI (and thus the PLs' interfaces to SPI)?

Hmm ... my first reaction was "sure", but:

regression=# create or replace function foo() returns setof text as $$
regression$# declare x record;
regression$# begin
regression$# for x in explain select * from tenk1 where unique1 = 42
regression$# loop
regression$# return next x."QUERY PLAN";
regression$# end loop;
regression$# return;
regression$# end$$ language plpgsql;
CREATE FUNCTION
regression=# select * from foo();
ERROR: cannot open non-SELECT query as cursor
CONTEXT: PL/pgSQL function "foo" line 3 at for over select rows

(And no, EXECUTE doesn't help.) This seems like an oversight. We
already have some understanding in the backend that certain utility
commands return query results; the SPI code should be letting those
results be scanned as if they were ordinary SELECT results.

regards, tom lane

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Michael Fuhr 2005-02-10 05:01:41 Re: a SELECT FOR UPDATE question
Previous Message Oisin Glynn 2005-02-10 04:28:12 Re: Functions with more than 32 parameters