Re: [GENERAL] identifying performance hits: how to ???

By asking about missing something fundamental, you have invited
less-than-expert feedback (i.e. feedback from me).

'adding a record doubles the retrieval time' makes it sound as though
somewhere in your query to populate the grid control you are requiring a
combinatorial operation (that is, "compare every record in table A with
every record in table B"). This, of course, assumes that there is some
discrepancy between what you are running on Postgres and what you tried on
Windows NT (MS-SQL?).

David Boerwinkle
-----Original Message-----
From: Robert Wagner <rwagner(at)siac(dot)com>
To: pgsql-general(at)postgresql(dot)org <pgsql-general(at)postgresql(dot)org>
Cc: squires(at)com(dot)net <squires(at)com(dot)net>
Date: Wednesday, January 12, 2000 9:56 AM
Subject: [GENERAL] identifying performance hits: how to ???

>Hello All,
>
>Anyone know if read performance on a postgres database decreases at an
>increasing rate, as the number of stored records increase?
>
>This is a TCL app, which makes entries into a single, table and from time
>to time repopulates a grid control. It must rebuild the data in the grid
>control, because other clients have since written to the same table.
>
>It seems as if I'm missing something fundamental... maybe I am... is some
>kind of database cleanup necessary? With less than ten records, the grid
>populates very quickly. Beyond that, performance slows to a crawl, until
>it _seems_ that every new record doubles the time needed to retrieve the
>records. My quick fix was to cache the data locally in TCL, and only
>retrieve changed data from the database. But now as client demand
>increases, as well as the number of clients making changes to the table,
>I'm reaching the bottleneck again.
>
>The client asked me yesterday to start evaluating "more mainstream"
>databases, which means that they're pissed off. Postgres is fun to work
>with, but it's hard to learn about, and hard to justify to clients.
>
>By the way, I have experimented with populating the exact same grid control
>on Windows NT, using MS Access (TCL runs just about anywhere). The grid
>seemed to populate just about instantaneously. So, is the bottleneck in
>Unix, in Postgres, and does anybody know how to make it faster?
>
>Cheers,
>Rob
>
>
>
>************
>