Re: Speeds using a transaction vrs not - Mailing list pgsql-sql

Thanks.

I guess I could add that logic, but this is a one time process going to run
the night we go live on postgres.
With .net it took like 2 hours to do the whole shebang, so I am happy.

But I was curious as we will be using odbc for our asp (aprx 90% of our
app).

I could test wrapping the .net in a transaction the way I do in odbc, but
you indicate it is doing that behind the scenes.

So far progress is going really great on our conversion.
I cant wait to see us up on the new platform.

I have not researched the details on doing autovacuum and backup.
I have tested manually backing up and restoring.

We are only like 10% done converting the code (I had hoped it going faster,
but I have not been hands on helping, so maybe it go faster when I get time
to start helping).

I did convert a fairly large app and it seemed to run faster on the postgres
box then the MSSQL box, so my first project after actually getting the data
and views has gone very smooth.

Everyone has been so helpful on the lists and that is the only reason I am
where I am so far so thanks again to everyone who has bothered to answer my
noob questions.

Joel Fradkin
Wazagua, Inc.
2520 Trailmate Dr
Sarasota, Florida 34243
Tel.  941-753-7111 ext 305
jfradkin@wazagua.com
www.wazagua.com
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-----Original Message-----
From: Richard Huxton [mailto:dev@archonet.com]
Sent: Thursday, February 24, 2005 9:21 AM
To: Joel Fradkin
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Speeds using a transaction vrs not

Joel Fradkin wrote:
> No I did not do it in on transaction (although in .net I never started or
> commited a transaction.

All inserts/updates/etc take place within a transaction with PostgreSQL.
Some client libraries autocommit for you - you'll need to read the
documentation.

> ODBC :
> myCommand.CommandText = insertsqltext
> myCommand.ExecuteNonQuery()
> myTrans.Commit()
>
> .net driver:
> Dim cmd As New NpgsqlCommand(insertsqltext, cnn)
> cmd.ExecuteNonQuery()
> cmd.Dispose()

Both look to me like they are producing one transaction per insert (the
slowest possible way to bulk-copy data). That's assuming each block of
commands is within one loop.

Precisely what is happening will be easiest to see by turning statement
logging on in your postgresql.conf and comparing two runs. The delay
might be in overheads of setting up the transaction etc. with the ODBC
driver.

In any case, if bulk-copying data you'll find a huge improvement
grouping rows together in batches of 100 - 10,000.

--  Richard Huxton  Archonet Ltd