Re: [PATCHES] Bitmapscan changes

On Mar 21, 2007, at 5:22 PM, Heikki Linnakangas wrote:

> 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.

Sure, I'll check it with my network statistics thingie. 30GB db atm,  
with milions of rows. (traffic analysies for wide network , ethernet  
level, from/to/protocol/size kinda of thing). Loads of updates on 2  
tables (that's where I also see HOT would benefit me).


-- 
Grzegorz Jaskiewicz

C/C++ freelance for hire