Tom Lane wrote:
> OK, I've reproduced the test case locally. I believe that when you> say "worse", you mean "worse than 8.3", right?
Andyou did tell me> offlist that you were testing with --enable-cassert. CVS HEAD has> very substantially greater
cassertoverhead because of the> randomize_memory addition --- oprofile output for this test looks like>> samples %
image name symbol name> 1239580 78.7721 postgres randomize_mem> 143544 9.1218
libc-2.7.so memcpy> 48039 3.0528 libc-2.7.so memset> 13838 0.8794 postgres
LWLockAcquire> 12176 0.7738 postgres index_getnext> 11697 0.7433 postgres
LWLockRelease> 10406 0.6613 postgres hash_search_with_hash_value> 4739 0.3012 postgres
toast_fetch_datum> 4099 0.2605 postgres _bt_checkkeys> 3905 0.2482 postgres
AllocSetAlloc> 3751 0.2384 postgres PinBuffer> 3545 0.2253 postgres
UnpinBuffer>>I'm inclined to think that we'd better turn that off by default,> since it's not looking like it's
catchinganything new.
Yes, I suspect that's probably it. I applied the patch straight to CVS
tip as I wasn't aware of any changes that would affect the unpatched
result, but I was obviously wrong ;)
(cut)
> On the whole I'm still feeling pretty discouraged about this patch ...
At the very least we have some more information on how an eventual
solution should work, and a test case to help analyse the effectiveness
of any potential solution.
ATB,
Mark.
--
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
T: +44 870 608 0063
