One other possible reason for splitting the table up in two chunks is to grant different rights on the 2 sets of columns.
Susan Cassidy
Bill Moseley <moseley@hank.org> Sent by: pgsql-general-owner@postgresql.org
05/15/2007 09:44 AM
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Postgres General <pgsql-general@postgresql.org>
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Re: [GENERAL] Performance issues of one vs. two split tables.
Sorry, I don't mean to drag this thread out much longer. But, I have one more question regarding joins.
Say I have a customer table and an order table. I want a list of all order id's for a given customer.
SELECT o.id FROM order o JOIN customer c on o.customer = c.id
Does that bring into memory all columns from both order and customer? Maybe that's not a good example due to indexes.
See, I've seen this splitting of one-to-one tables a number of time (such as the user and user_preferences example) and I'm not sure if that's just poor schema design, premature optimization, or someone making smart use of their knowledge of the internal workings of Postgresql....
-- Bill Moseley moseley@hank.org
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