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.