based on the problem I had here
I thought it would be interesting to know why UseDeclareFetch is slowing my
query down dramatically.
I have a table containing 50 tuples and retrieve all 50 tuples with a bound
column select statement:
SELECT * FROM tblItem WHERE intItemIDCnt = ?
This takes 8 seconds (over a slow DSL connection with 150ms ping). Tom Lane
suggested enabling UseDeclareFetch and the performance drop was significant:
Instead of 8 seconds, the query now takes 30-32 seconds. I also tested
enabling UseServerSidePrepare (without UseDeclareFetch) and the query was
executed in 7 seconds.
After rewriting the query to use an IN clause it now works perfect:
SELECT * FROM tblItem WHERE intItemIDCnt IN (...)
The result is retrieved in 400ms (UseServerSidePrepare=950ms and
The only thread I found discussing the UseDeclareFetch/UseServerSidePrepare
options was <http://archives.postgresql.org/pgsql-odbc/2006-10/msg00051.php>.
So my questions are
1) Is there any chance the driver itself could be enhanced like Dimitri
2) When should UseServerSidePrepare be used?
3) When should UseDeclareFetch be used?
pgsql-odbc by date
|Next:||From: Richard Wesley||Date: 2007-06-25 16:28:34|
|Subject: Re: Using the PostgreSQL ODBC driver for another database|
|Previous:||From: Mark Cave-Ayland||Date: 2007-06-22 08:29:44|
|Subject: Re: Proposal for new pgsqlODBC feature - hidingtables inaccessible to the current user|