Date: 22 Nov 2002 09:37:34 -0700
Message-ID: <87of8ha7ch.fsf@openinformatics.com>
From: "Jason E. Stewart" <jason@openinformatics.com>
To: pgsql-interfaces@postgresql.org
Subject: Re: Frontend/Backend protocol changes?
In-Reply-To: <200211221546.gAMFkBi21622@candle.pha.pa.us>
Lines: 32
User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.4 (Honest Recruiter)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

Hey all,

I'm not sure if this is the correct list to ask this question, so I
appologize ahead of time if it is misguided.

I'm using DBD::Pg to insert large amounts of data into a Postgres
installation. We will occassionally (once every few weeks, perhaps)
get new chip layouts that need to be added. Each layout may have up to
250k spots which go into a Spot table. 

My current code is glacially slow - on an otherwise zippy
dual-processor P4, it seems this insert will take 3 days.

I've gotten a bit of feedback from the Perl dbi-users list:

1) Transactions: My current approach was to do this inside a
   transaction, but apparently the write-ahead-logging will not handle
   250k logged inserts well.

   Is this true, and I should commit after every 20 or so spots?

2) Indices: apparently every insert updates the indices on the
   table. From my reading of the documentation, the indices aren't
   updated inside a transaction, but instead at the end.

3) COPY: I could use COPY, but apparently triggers are not, well,
   triggered under COPY. 

   Is this true? I have datestamps on my inserts for audit trails.

Thanks ahead of time for any help,
jas.