To: Simon Riggs <simon@2ndquadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>,  Andrew Sullivan <ajs@crankycanuck.ca>,
	pgsql-performance@postgresql.org
Subject: Re: Some queries starting to hang
References: <1149534308.3583.56.camel@bg002441.pro-unlimited.com>
	<22706.1149538039@sss.pgh.pa.us>
	<20060605203851.GB7071@phlogiston.dyndns.org>
	<23915.1149541591@sss.pgh.pa.us>
	<1149604741.2621.487.camel@localhost.localdomain>
	<17148.1149605005@sss.pgh.pa.us>
	<1149605576.2621.502.camel@localhost.localdomain>
In-Reply-To: <1149605576.2621.502.camel@localhost.localdomain>
From: Greg Stark <gsstark@mit.edu>
Organization: The Emacs Conspiracy; member since 1992
Date: 06 Jun 2006 11:37:46 -0400
Message-ID: <87ejy29tx1.fsf@stark.xeocode.com>
Lines: 19
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

Simon Riggs <simon@2ndquadrant.com> writes:

> The idea I just had was: why do we need EXPLAIN ANALYZE to run to
> completion? In severe cases like this thread, we might be able to
> discover the root cause by a *partial* execution of the plan, as long as
> it was properly instrumented. That way, the OP might have been able to
> discover the root cause himself...

An alternate approach would be to implement a SIGINFO handler that prints out
the explain analyze output for the data built up so far. You would be able to
keep hitting C-t and keep getting updates until the query completes or you
decided to hit C-c.

I'm not sure how easy this would be to implement but it sure would be nice
from a user's point of view. Much nicer than having to specify some arbitrary
limit before running the query.

-- 
greg