From: | PFC <lists(at)peufeu(dot)com> |
---|---|
To: | Andrus <kobruleht2(at)hot(dot)ee>, tv(at)fuzzy(dot)cz |
Cc: | "Richard Huxton" <dev(at)archonet(dot)com>, pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Hash join on int takes 8..114 seconds |
Date: | 2008-11-21 19:08:27 |
Message-ID: | op.ukzgsdn2cigqcu@soyouz |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
> log file seems that mostly only those queries are slow:
>
> SELECT ...
> FROM dok JOIN rid USING (dokumnr)
> JOIN ProductId USING (ProductId)
> WHERE rid.ProductId LIKE :p1 || '%' AND dok.SaleDate>=:p2
>
> :p1 and :p2 are parameters different for different queries.
>
> dok contains several years of data. :p2 is usually only few previous
> months
> or last year ago.
> SELECT column list contains fixed list of known columns from all tables.
>
> How to create index or materialized view to optimize this types of
> queries ?
>
I would remove some granularity, for instance create a summary table
(materialized view) by month :
- date (contains the first day of the month)
- product_id
- total quantity, total price sold in given month
You get the idea.
If your products belong to categories, and you make queries on all the
products in a category, it could be worth making a summary table for
categories also.
From | Date | Subject | |
---|---|---|---|
Next Message | Andrus | 2008-11-21 19:10:21 | Re: Hash join on int takes 8..114 seconds |
Previous Message | Andrus | 2008-11-21 19:00:09 | Re: Hash join on int takes 8..114 seconds |