Re: Updated bitmap index patch

Finlay,

Thanks for testing. If you can send me the schema, that would be great.

Thanks,
Jie

On 5/4/07 5:41 AM, "Finlay Thompson" <finlay(at)catalyst(dot)net(dot)nz> wrote:

> Hi Gavin
>
> Thanks for the new patch!
>
> I ran some address matching on the patched code and have generated
> another "ERROR: out of memory" problem.
>
> The strange thing is that it runs over 150 queries without problem and
> then crashes.
>
> I have attached the logfile (well some of it).
>
> If you want I can send you the schema as well....
>
>
> Finlay
>
>
> On Thu, 2007-05-03 at 13:51 +1000, Gavin Sherry wrote:
>> Hi all,
>>
>> Attached is an updated bitmap index patch. It contains bug fixes, API
>> changes, binary changes (page identifier to distinguish it from other
>> indexes) and has been brought up to HEAD.
>>
>> I worked on a few approaches to VACUUM, none very satisfactory. The
>> problem is, breaking a compressed word representing matches can have
>> serious consequences -- at the least, creation of new words, at the worst,
>> creation of a new page. If a lot of this were to happen, REINDEX would be
>> much more efficient (this is what earlier patches did).
>>
>> One approach I looked at was modifying the existing read API to be able to
>> do something like "kill prior tuple". This, I think, made the API quite
>> complex and it was hard to implement, since the existing mechanism
>> decompresses words on the fly and it would be hard to identify which TID
>> is no longer a match. So, I dropped this idea pretty quickly.
>>
>> The second approach is to just manually traverse each vector and change
>> matches to non-matches where necessary. The complexity then is in managing
>> the consequences of breaking compressed words, doing WAL (efficiently) and
>> calculating free space. I've only partially implemented this approach. At
>> this stage, I don't have time to finish it due to other commitments.
>>
>> Thanks,
>>
>> Gavin
>> ---------------------------(end of broadcast)--------------------------- TIP
>> 2: Don't 'kill -9' the postmaster
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match