Date: Fri, 6 Sep 2013 15:12:07 +0200
From: Andres Freund <andres@2ndquadrant.com>
To: Hannu Krosing <hannu@2ndQuadrant.com>
Cc: Dimitri Fontaine <dimitri@2ndQuadrant.fr>,
 Alvaro Herrera <alvherre@2ndquadrant.com>,
 Bruce Momjian <bruce@momjian.us>, Robert Haas <robertmhaas@gmail.com>,
 Peter Geoghegan <peter@2ndquadrant.com>,
 Tom Lane <tgl@sss.pgh.pa.us>, Andrew Dunstan <andrew@dunslane.net>,
 PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: [PERFORM] encouraging index-only scans
Message-ID: <20130906131207.GC600952@alap2.anarazel.de>
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On 2013-09-06 13:38:56 +0200, Hannu Krosing wrote:
> On 09/06/2013 09:23 AM, Dimitri Fontaine wrote:
> > Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> >> I'm not sure if we need to expose all these new maintenance actions as
> >> SQL commands.
> > I strongly think we should, if only for diagnostic purposes. 
> It would be much easier and more flexible to expose them
> as pg_*() function calls, not proper "commands".

I don't think that's as easy as you might imagine. For much of what's
done in that context you cannot be in a transaction, you even need to be
in a toplevel statement (since we internally
CommitTransactionCommand/StartTransactionCommand).

So those pg_* commands couldn't be called (except possibly via the
fastpath function call API ...) which might restrict their usefulnes a
teensy bit ;)

So, I think extending the options passed to VACUUM - since it can take
pretty generic options these days - is a more realistic path.

> > Also to
> > adapt to some well defined workloads that the automatic system is not
> > designed to handle.
> +1

What would you like to expose individually?

Greetings,

Andres Freund

-- 
 Andres Freund	                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services


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