Re: Removing freelist (was Re: Should I implement DROP INDEX CONCURRENTLY?) - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Removing freelist (was Re: Should I implement DROP INDEX CONCURRENTLY?)
Date
Msg-id 2096.1327295568@sss.pgh.pa.us
Whole thread Raw
In response to Re: Removing freelist (was Re: Should I implement DROP INDEX CONCURRENTLY?)  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Removing freelist (was Re: Should I implement DROP INDEX CONCURRENTLY?)  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Sat, Jan 21, 2012 at 5:29 PM, Jim Nasby <jim@nasby.net> wrote:
>> We should also look at having the freelist do something useful, instead of just dropping it completely.
Unfortunatelythat's probably more work...
 

> That's kinda my feeling as well.  The free list in its current form is
> pretty much useless, but I don't think we'll save much by getting rid
> of it, because that's just a single test.  The expensive part of what
> we do while holding BufFreelistLock is, I think, iterating through
> buffers taking and releasing a spinlock on each one (!).

Yeah ... spinlocks that, by definition, will be uncontested.  So I think
it would be advisable to prove rather than just assume that that's a
problem.
        regards, tom lane


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