From: David Hartwig <daveh@insightdist.com>
To: Christian Steindl <e9425178@student.tuwien.ac.at>
Cc: pgsql-interfaces@postgreSQL.org
Subject: Re: [INTERFACES] scrollable cursor via odbc
Date: Mon, 29 Jun 1998 14:45:16 -0400
Message-ID: <3597E0BB.DA0DF3DA@insightdist.com> (raw)
References: <Pine.A41.3.95.980629182008.74084A-100000@stud1.tuwien.ac.at>
Christian,
The problem is in the backend optimizer. If you turn on the commlog, you
will find that queries are being generated with lots of ORs. This is to get
a record set. If you run that query with EXPLAIN you will find that it is
doing a sequential scan. (Maybe several per page scroll.) Even worse, if
you have a multi-part key, the optimizer will spend (expend) much resource
CNFifying the where clause.
I am working on a patch to resolve this in the backend. I have a workable
solution, for queries with this particular signature, but I am trying to
make it more general purpose in nature.
Christian Steindl wrote:
> i use the odbc interface to the postgresql but it seems to be quite
> slowly.
> although it's a single table with about 20.000 rows.
> i set a link in an access-db and scrolling (next page, last row) is very
> slowly.
> is there a way to optimize the performance?
> can i use scrollable cursor via the odbc-drv?
>
> best regards
>
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To: pgsql-interfaces@postgresql.org
Cc: daveh@insightdist.com, e9425178@student.tuwien.ac.at
Subject: Re: [INTERFACES] scrollable cursor via odbc
In-Reply-To: <3597E0BB.DA0DF3DA@insightdist.com>
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