Re: patch : Allow toast tables to be moved to a different tablespace - Mailing list pgsql-hackers

From Andres Freund
Subject Re: patch : Allow toast tables to be moved to a different tablespace
Date
Msg-id 20150707120744.GM30359@alap3.anarazel.de
Whole thread Raw
In response to Re: patch : Allow toast tables to be moved to a different tablespace  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: patch : Allow toast tables to be moved to a different tablespace  (Jim Nasby <Jim.Nasby@BlueTreble.com>)
List pgsql-hackers
On 2015-07-03 18:03:58 -0400, Tom Lane wrote:
> I have just looked through this thread, and TBH I think we should reject
> this patch altogether --- not RWF, but "no we don't want this".  The
> use-case remains hypothetical: no performance numbers showing a real-world
> benefit have been exhibited AFAICS.

It's not that hard to imagine a performance benefit though? If the
toasted column is accessed infrequently/just after filtering on other
columns (not uncommon) it could very well be beneficial to put the main
table on fast storage (SSD) and the toast table on slow storage
(spinning rust).

I've seen humoungous toast tables that are barely ever read for tables
that are constantly a couple times in the field.



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