Message-ID: <511CBC55.9080804@lignano.it>
Date: Thu, 14 Feb 2013 11:28:37 +0100
From: Asmir Mustafic <goetas@lignano.it>
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To: pgsql-performance@postgresql.org
Subject: 700K Inserts in transaction
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Hi everybody!
I'm new in mailing list, and i have a little question.


The tables are:
postalcodes (place_id, code),  PK(place_id, code) 600K of rws
places (id, name),  PK(id), INDEX(name) 3M of rows

I've to insert another 600k of rows into postalcodes table, in a single 
transaction, omitting duplicates.

The insert query is a prepared statement like this:

INSERT INTO postalcodes (place_id, code)
SELECT places.id, :code
FROM places
LEFT JOIN postalcodes (postalcodes.place_id = places.id and 
postalcodes.code = :code)
WHERE places.name = :name AND postalcodes.place_id IS NULL

Inserting rows works well (3000 queries per second), but when i reach 
30K of executed statements, the insert rate slows down to 500/1000 
queries per second).

Doing a commit every 20K of inserts, the insert rate remain 3000 queries 
per second.

There is a limit of inserts in a transaction?


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