Re: Joins on over 10 tables returns unreliable results

pgsql-bugs(at)postgresql(dot)org writes:

> Running Postgres version 7.01 on Redhat linux 6.2. When joining on
> more than 10 tables not all of the expected results are returned.
> The query can be repeated several times, with different result sets
> when the data itself is static. The most common result is the return
> of only one record. 11 tables seems to be the magic limit. Joins on
> 10 tables works without a hitch. This join was based on a column id
> that exists in all of the tables.

This seems to be a problem in the genetic query optimizer. But to examine
closer we'd really need to get sample data and queries to reproduce this.

For now you can SET geqo TO 'off'; to disable this.

--
Peter Eisentraut peter_e(at)gmx(dot)net http://yi.org/peter-e/