Robert Haas wrote:
On Mon, Feb 13, 2012 at 7:45 AM, Robert Haas<>  wrote:
On Thu, Feb 9, 2012 at 3:37 PM, Jay Levitt<>  wrote:
So my pre-built 9.1.2 takes 434s, my source-built 9.2 takes 509s, and
(probably both of our) 9.1-HEAD takes 1918s... is that something to worry
about, and if so, are there any tests I can run to assist? That bug doesn't
affect me personally, but y'know, community and all that.  Also, I wonder if
it's something like "9.2 got way faster doing X, but meanwhile, HEAD got way
slower doing Y.", and this is a canary in the coal mine.
This might be a lame hypothesis, but... is it possible that you built
your 9.1-tip binaries with --enable-cassert?  Or with different
optimization options?

No, I think I/O just varies more than my repeated tests on 1M rows indicated. I ran the 10M-row test four times on the same server, alternating between packaged 9.1.2 and source-built 9.1.2 (default configure options), and saw these times:

apt     76      578
source  163     636
apt     73      546
source  80      473

EBS has no performance guarantees at all; you share your disks with an arbitrary number of other users, so if someone "in the neighborhood" decides to do some heavy disk I/O, you lose. Let this be a lesson to me: run benchmarks locally!

So I tested.  On my MacBook Pro, your test script builds the index in
just over 25 s on both REL9_1_2 and this morning's REL9_1_STABLE.

I think that's the 1-million version I emailed; try adding a zero and see if it doesn't take a little longer.


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