Re: effective_io_concurrency

Peter Geoghegan <peter@2ndquadrant.com>

From: Peter Geoghegan <peter@2ndquadrant.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2012-08-30T20:25:44Z
Lists: pgsql-hackers
On 30 August 2012 20:28, Robert Haas <robertmhaas@gmail.com> wrote:
> On Sat, Jul 28, 2012 at 4:09 PM, Jeff Janes <jeff.janes@gmail.com> wrote:
>> But it might be better yet to make ordinary index scans benefit from
>> effective_io_concurrency, but even if/when that gets done it would
>> probably still be worthwhile to make the planner understand the
>> benefit.
>
> That sounds good too, but separate.

Indeed. The original effective_io_concurrency commit message said:

"""
***SNIP***

(The best way to handle this for plain index scans is still under debate,
so that part is not applied yet --- tgl)
"""

...seems like a pity that this debate never reached a useful conclusion.

Just how helpful is effective_io_concurrency? Did someone produce a
benchmark at some point?

-- 
Peter Geoghegan       http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training and Services