Обсуждение: Question about DBCP prepared statement pooling with postgres

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Question about DBCP prepared statement pooling with postgres

От
"George Woodring"
Дата:
We are looking at implementing prepared statement pooling and I have a
question if it provides any gains with a heavily updated database.  I am
worried that the query plans will become stale an inefficient.

A coworker mentioned "jdbc prepared statement" != "psql or perl prepared
statement" and it is recommended for web environments (which we are).

Any suggestions would be appreciated.

Thanks,
Woody

----------------------------------------
iGLASS Networks
211-A S. Salem St
Apex NC 27502
(919) 387-3550 x813
www.iglass.net

Re: Question about DBCP prepared statement pooling with

От
Mark Lewis
Дата:
If the heavily updated database is so heavily updated that statistics
are wildly volatile, such as one table having 5 million rows one minute
and a dozen the next minute, then back to 5 million, then you probably
don't want to use server-side prepared plans.

More likely however is that even if your database is heavily updated,
the average statistical properties of the tables don't change much, in
which case using server-side prepared plans is usually a good thing.

If you've decided that the statistical distribution of your data doesn't
change too much and you'd like to use server-side prepared plans, then
look at the docs here for how to make JDBC PreparedStatement == Server
prepared plan: http://jdbc.postgresql.org/documentation/81/server-
prepare.html

-- Mark Lewis

On Wed, 2006-03-01 at 17:00 -0500, George Woodring wrote:
> We are looking at implementing prepared statement pooling and I have a
> question if it provides any gains with a heavily updated database.  I am
> worried that the query plans will become stale an inefficient.
>
> A coworker mentioned "jdbc prepared statement" != "psql or perl prepared
> statement" and it is recommended for web environments (which we are).
>
> Any suggestions would be appreciated.
>
> Thanks,
> Woody
>
> ----------------------------------------
> iGLASS Networks
> 211-A S. Salem St
> Apex NC 27502
> (919) 387-3550 x813
> www.iglass.net
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster