Re: [PoC] Improve dead tuple storage for lazy vacuum

Hi,

On 2021-07-19 16:49:15 -0700, Andres Freund wrote:
> E.g. for
>
> select prepare(
> 1000000, -- max block
> 20, -- # of dead tuples per page
> 10, -- dead tuples interval within a page
> 1 -- page inteval
> );
> attach size shuffled ordered
> array 69 ms 120 MB 84.87 s 8.66 s
> intset 173 ms 65 MB 68.82 s 11.75 s
> rtbm 201 ms 67 MB 11.54 s 1.35 s
> tbm 232 ms 100 MB 8.33 s 1.26 s
> vtbm 162 ms 58 MB 10.01 s 1.22 s
> radix 88 ms 42 MB 11.49 s 1.67 s
>
> and for
> select prepare(
> 1000000, -- max block
> 10, -- # of dead tuples per page
> 1, -- dead tuples interval within a page
> 1 -- page inteval
> );
>
> attach size shuffled ordered
> array 24 ms 60MB 3.74s 1.02 s
> intset 97 ms 49MB 3.14s 0.75 s
> rtbm 138 ms 36MB 0.41s 0.14 s
> tbm 198 ms 101MB 0.41s 0.14 s
> vtbm 118 ms 27MB 0.39s 0.12 s
> radix 33 ms 10MB 0.28s 0.10 s

Oh, I forgot: The performance numbers are with the fixes in
https://www.postgresql.org/message-id/20210717194333.mr5io3zup3kxahfm%40alap3.anarazel.de
applied.

Greetings,

Andres Freund