| From: | Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Tatsuo Ishii <ishii(at)postgresql(dot)org>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: pgbench --latency-limit option |
| Date: | 2015-12-23 18:06:42 |
| Message-ID: | alpine.DEB.2.10.1512231903580.22350@sto |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
>> [...]
>> Because the schedule is based on a stochastic process, transactions are not
>> set regularly (that would induce patterns and is not representative of
>> real-life load) but randomly.
>>
>> The long term average is expected to converge to 2 tps, but on a short run
>> it may differ significantly.
>
> Hmm. Is that documented somewhere?
Sure, see --rate option in pgbench doc, which states:
"The rate is targeted by starting transactions along a Poisson-distributed
schedule time line."
The impact on the tps is implied, though.
--
Fabien.
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