Re: [PATCHES] Bitmapscan changes

Grzegorz Jaskiewicz wrote:
>
> On Mar 19, 2007, at 11:16 AM, Heikki Linnakangas wrote:
>
>> Grzegorz Jaskiewicz wrote:
>>> On Mar 16, 2007, at 10:12 PM, Heikki Linnakangas wrote:
>>>> You'll obviously need to run it with the patch applied. I'd suggest
>>>> to enable stats_block_level to see the effect on buffer cache
>>>> hit/miss ratio.
>>> groupeditems-42-pghead.patch.gz is enough, or it needs
>>> maintain_cluster_order_v5.patch ??
>>
>> No, it won't make a difference unless you're inserting to the table,
>> and the inserts are not in cluster order.
> well, that's okay than. I see really good improvement in terms of speed
> and db size (which reflects obviously in i/o performance).
> Let me know if further testing can be done. I would happily see it in
> mainline.

If you have a real-world database you could try it with, that would be
nice. The test I sent you is pretty much a best-case scenario, it'd be
interesting to get anecdotal evidence of improvements in real applications.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com