Josh Berkus <[EMAIL PROTECTED]> writes: > Hmmm. Your results are withing the margin of error for DBT2, so they > show no real difference. What we need for this is a heavy-read > workload, though; on a workload like DBT2 (which is mostly writes) I > wouldn't expect lazy-XID to help much.
Lazy-XID doesn't help on a write-mostly workload, but I would have expected to see some benefit from the latestCompletedXid patch. The rough tests I just finished suggest that the win to look for is improvement of the very tail of the distribution --- well beyond the 90th percentile point which is the most we can see in Markus' printout. Can we get 95% and 99% response time percentiles? For comparison, in my little test I got 0.828546 vs 0.873957 as the 99% percentile pgbench transaction times. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate