On 2020-10-30 02:43, Masahiko Sawada wrote:
> Using the integer set is very memory efficient (5MB vs. 114MB in the
> base case) and there is no 1GB limitation. Looking at the execution
> time, I had expected that using the integer set is slower on recording
> TIDs than using the simple array but in this experiment, there is no
> big difference among methods. Perhaps the result will vary if vacuum
> needs to record much more dead tuple TIDs. From the results, I can see
> a good improvement in the integer set case and probably a good start
> but if we want to use it also for lazy vacuum, we will need to improve
> it so that it can be used on DSA for the parallel vacuum.
>
> I've attached the patch I used for the experiment that adds xx_vacuum
> GUC parameter that controls the method of recording TIDs. Please note
> that it doesn't support parallel vacuum.
How do you want to proceed here? The approach of writing a wrapper for
bsearch with bound check sounded like a good start. All the other ideas
discussed here seem larger projects and would probably be out of scope
of this commit fest.
