Re: Re: GiST optimizing memmoves in gistplacetopage for fixed-size updates [PoC]

>Can you please patch BRIN to use this new function too?

On my machine replacement of both BRIN update cases (see
https://github.com/x4m/pggistopt/commit/a6d301ff79104b977619339d53aebf748045418a
) showed no performance changes on folowing update query (6 seconds of
updates avg):
create table dataTable(x int, y int);
insert into dataTable(x,y) select x,y from generate_series(1,1e3,1)
x,generate_series(1,1e3,1) y;
create index idx on dataTable using brin(x,y);
update datatable set x = random()*1024, y = random()*1024;

https://gist.github.com/x4m/7e69fd924b9ffd2fdc9c6100e741171d

Probably I was looking in a wrong place. I do not see other cases when
PageIndexTupleOverwrite can improve performance of BRIN. Though I'll
make PageIndexTupleOverwrite BRIN-compatible in forthcoming patch
version: BRIN  tuples have no length in header and it must be taken as
a parameter. Just as the PageAddItem do.


Best regards, Andrey Borodin, Octonica & Ural Federal University.