Re: recursive query returning extra rows in 8.4

David Johnston <polobo(at)yahoo(dot)com> writes:
> chris smith-9 wrote
>> Using postgres 8.4.13 (latest that redhat provides in rhel6) the query
>> below returns an extra row compared to running the same thing in later
>> versions (tried 9.0, 9.1, 9.2 - they don't return the extra row).

> Likely this is a bug that was fixed in one of the five newer 8.4 point
> releases. You can use "SELECT DISTINCT *" to get rid of the extra data if
> you choose not to upgrade.

In particular I think this matches the first item in the 8.4.14 release
notes:

* Fix planner's assignment of executor parameters, and fix executor's
rescan logic for CTE plan nodes (Tom Lane)

These errors could result in wrong answers from queries that scan the
same WITH subquery multiple times.

When I worked for Red Hat, it was hard to get permission to push PG update
releases unless a nontrivial security fix was involved. That's probably
why they're still on 8.4.13. You could file a bug asking for an update
because of this issue, but I can't say how quickly anything would happen.

regards, tom lane