Re: What's faster?

On December 26, 2003 07:11 pm, Keith Bottner wrote:
> I have a database where the vast majority of information that is related to
> a customer never changes. However, there is a single field (i.e. balance)
> that changes potentially tens to hundreds of times per day per customer
> (customers ranging in the 1000s to 10000s). This information is not
> indexed. Because Postgres requires VACUUM ANALYZE more frequently on
> updated tables, should I break this single field out into its own table,
> and if so what kind of a speed up can I expect to achieve. I would be
> appreciative of any guidance offered.

We went through this recently. One thing we found that may apply to you is
how many fields in the client record have a foreign key constraint. We find
that tables with lots of FKeys are a lot more intensive on updates. In our
case it was another table, think of it as an order or header table with a
balance, that has over 10 million records. Sometimes we have 200,000
transactions a day where we have to check the balance. We eventually moved
every field that could possibly be updated on a regular basis out to separate
tables. The improvement was dramatic.

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