Hi, Oliver,
On Sun, 19 Sep 2004 09:29:04 +1200
Oliver Jowett <oliver@opencloud.com> wrote:
> However, with a 8.0 backend, if the planner benefits from knowing the
> particular parameter values in use for a particular query, then using an
> unnamed statement may be faster due to using an improved plan. Under 7.4
> there will be no difference; both named and unnamed statements will use
> the generic plan.
Quoting from http://developer.postgresql.org/beta-history.txt:
* Plan prepared queries only when first executed so constants can be
used for statistics (Oliver Jowett)
Prepared statements plan queries once and execute them many times.
While prepared queries avoid the overhead of re-planning on each
use, the quality of the plan suffers from not knowing the exact
parameters to be used in the query. In this release, planning of
unnamed prepared statements is delayed until the first execution,
and the actual parameter values of that execution are used as
optimization hints.
So it seems that your issue is addressed in 8.0 - as long as the Beta of
the Readme is correct :-)
HTH,
Markus
--
markus schaber | dipl. informatiker
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