On Jun 14, 2010, at 2:22 , Greg Smith wrote:
> Florian Pflug wrote:
>> To be able to asses the performance characteristics of the different wal-related options, I patched pgbench to show
theaverage latency of each individual statement. The idea is to be able to compare the latency of the COMMIT with the
onesof the other statements.
>
> That's an interesting idea, particularly given that people don't really understand where the time is going in the
standardpgbench test. Your first bit of review feedback is that this would have to be something you could toggle on
andoff, there's no way most people want to pay this penalty. If you submit a new patch with a command line option to
enablethis alternate logging format and add the result to https://commitfest.postgresql.org/action/commitfest_view?id=6
,you can put my name down as a reviewer and I'll take a deeper look at it as part of that.
Thank for offering to review this!
Here is an updated patch that adds a command-line option (-r) to enable/disable per-command latency reporting. It also
usesthe INSTR_TIME infrastructure that 9.0 provides, and should work correctly in multi-threaded mode. Data is
collectedper-thread and summarized only for reporting to avoid locking overhead. It now shows all lines for the SQL
scriptstogether with their latencies (zero for comments), not only those containing SQL commands.
I'll add this patch to the next commitfest, and put you down as a reviewer, as you suggested.
best regards,
Florian Pflug