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* random_page_cost for tablespace
@ 2009-11-09 12:58 Laszlo Nagy <gandalf@shopzeus.com>
0 siblings, 1 reply; 3+ messages in thread
From: Laszlo Nagy @ 2009-11-09 12:58 UTC (permalink / raw)
To: pgsql-performance
Hi All,
We have a bigger table with some million rows. Number of index scans is
high, number of seq reads is low. This table if often joined with
others... so we want to buy a new SSD drive, create a tablespace on it
and put this big table on it. Random read speed on SSD is identical to
seq read. However, I need to tell the optimizer that random_page_cost is
less for the new tablespace. Is there a way to do it?
Thanks,
Laszlo
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: random_page_cost for tablespace
@ 2009-11-09 13:48 Robert Haas <robertmhaas@gmail.com>
parent: Laszlo Nagy <gandalf@shopzeus.com>
0 siblings, 1 reply; 3+ messages in thread
From: Robert Haas @ 2009-11-09 13:48 UTC (permalink / raw)
To: Laszlo Nagy <gandalf@shopzeus.com>; +Cc: pgsql-performance
2009/11/9 Laszlo Nagy <gandalf@shopzeus.com>:
> We have a bigger table with some million rows. Number of index scans is
> high, number of seq reads is low. This table if often joined with
> others... so we want to buy a new SSD drive, create a tablespace on it
> and put this big table on it. Random read speed on SSD is identical to
> seq read. However, I need to tell the optimizer that random_page_cost is
> less for the new tablespace. Is there a way to do it?
I happen to be working on a patch for this exact feature. However,
even assuming it gets in, that means waiting for 8.5.
...Robert
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: random_page_cost for tablespace
@ 2009-11-09 16:04 Laszlo Nagy <gandalf@shopzeus.com>
parent: Robert Haas <robertmhaas@gmail.com>
0 siblings, 0 replies; 3+ messages in thread
From: Laszlo Nagy @ 2009-11-09 16:04 UTC (permalink / raw)
To: Robert Haas <robertmhaas@gmail.com>; +Cc: pgsql-performance
Robert Haas írta:
> 2009/11/9 Laszlo Nagy <gandalf@shopzeus.com>:
>
>> We have a bigger table with some million rows. Number of index scans is
>> high, number of seq reads is low. This table if often joined with
>> others... so we want to buy a new SSD drive, create a tablespace on it
>> and put this big table on it. Random read speed on SSD is identical to
>> seq read. However, I need to tell the optimizer that random_page_cost is
>> less for the new tablespace. Is there a way to do it?
>>
>
> I happen to be working on a patch for this exact feature. However,
> even assuming it gets in, that means waiting for 8.5.
>
That will be a very nice feature. Thank you! :-)
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2009-11-09 16:04 UTC | newest]
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2009-11-09 12:58 random_page_cost for tablespace Laszlo Nagy <gandalf@shopzeus.com>
2009-11-09 13:48 ` Robert Haas <robertmhaas@gmail.com>
2009-11-09 16:04 ` Laszlo Nagy <gandalf@shopzeus.com>
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