Re: 8.0beta5 results w/ dbt2

Mark Wong <markw(at)osdl(dot)org> writes:
> I have some initial results using 8.0beta5 with our OLTP workload.
> Off the bat I see about a 23% improvement in overall throughput.

Between beta4 and beta5? That's astonishing. We didn't really do very
much that was performance-focused. Digging in the CVS logs, I see only
some changes intended to speed up subtransaction commit, which I suppose
is not relevant to your benchmark, plus these two changes:

2004-11-16 22:13 neilc

* src/backend/access/: hash/hash.c, nbtree/nbtree.c:
Micro-optimization of markpos() and restrpos() in btree and hash
indexes. Rather than using ReadBuffer() to increment the reference
count on an already-pinned buffer, we should use
IncrBufferRefCount() as it is faster and does not require acquiring
the BufMgrLock.

2004-11-09 16:42 tgl

* src/backend/optimizer/util/clauses.c: Allow planner to fold
"stable" functions to constants when forming selectivity estimates,
per recent discussion.

Given the right sort of queries I suppose the second change might create
a significant improvement, but I wasn't expecting 23% on a
general-purpose benchmark...

regards, tom lane