Re: Minor optimizations in lazy_scan_heap - Mailing list pgsql-hackers

From Pavan Deolasee
Subject Re: Minor optimizations in lazy_scan_heap
Date
Msg-id CABOikdN2i2HVGB2V-S-pgmMysbgBtidcxXxi4eVoWhFR0Tyjnw@mail.gmail.com
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In response to Re: Minor optimizations in lazy_scan_heap  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers


On Tue, Dec 4, 2012 at 11:02 PM, Robert Haas <robertmhaas@gmail.com> wrote:
On Mon, Dec 3, 2012 at 1:23 AM, Pavan Deolasee <pavan.deolasee@gmail.com
>
> Comments ? Anyone thinks any/all of above is useful ?

I doubt that any of these things make enough difference to be worth
bothering with,

You're right. These are not big ticket optimisations, still I felt they are worth doing because tiny bits add up over a time and also because the code may become little simpler. The benchmarks don't show anything interesting though. The time taken to scan 100K+ bits is sub-second. So even when I tried with the attached patch, the numbers did not show any noticeable difference. It might be worth trying with a table with 1M or 10M data blocks, but I don't have such a hardware to test.

The patch itself can be improved further, especially we can possibly optimise the loop and test 32-bits at a time, instead of 8 I am doing currently. Not sure its worth though.

Thanks,
Pavan

--
Pavan Deolasee
http://www.linkedin.com/in/pavandeolasee
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