[DB-SIG] Python/PostgreSQL API performance comparison (update)
chris at cogdon.org
Sun May 25 14:48:34 EDT 2003
On Sunday, May 25, 2003, at 13:34 US/Pacific, Marcos Sánchez Provencio
> One note for multithreaded appserver (webware, zope...). Due to the
> global lock, the DBMS and the app act funny regarding balance of load.
> If the app is too heavy, it can suck up one CPU while the other is
> idle. In this case, it would be worth to pass some load to the DBMS.
Unfortunately, in terms of CPU utilisation I don't think it's passing
load to the DMBS, but just creating EXTRA load on the DMBS. Compare the
'user' times in both cases. The 'declare cursor' version actually
consumes a small amount extra, but a LOT of extra real time. Viz:
> PgSQL [ 3.650, 0.010, 0.000, 0.000, 41.150 ]
> PgSQL (nocursor) [ 3.620, 0.010, 0.000, 0.000, 32.320 ]
However, if memory is an issue, and you're expecting really large
datasets, then I can see that being an advantage.
("`-/")_.-'"``-._ Chris Cogdon <chris at cogdon.org>
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