Re: Yet another fast GiST build

On Thu, Nov 05, 2020 at 10:11:52PM +0500, Andrey Borodin wrote:
> To test that functions are actually called for sorting build we should support directive sorting build like "CREATE INDEX ON A USING GIST(B) WITH(sorting=surely,and fail if not)".

Maybe you could add a DEBUG1 message for that, and include that in regression
tests, which would then fail if sorting wasn't used.

Maybe you'd need to make it consistent by setting GUCs like work_mem /
max_parallel_maintenance_workers / ??

Similar to this

postgres=# SET client_min_messages =debug;
postgres=# CREATE INDEX ON A USING GIST(i) WITH(buffering=off);
DEBUG: building index "a_i_idx2" on table "a" serially
CREATE INDEX

> If we have unconditional sorting build and unconditional buffered build we can check opclasses code better.
> The problem is current reloption is called "buffering". It would be strange if we gave this enum possible value like "not buffering, but very much like buffering, just another way".
> How do you think, is it ok to add reloption "buffering=sorting" to enhance tests?
>
> Best regards, Andrey Borodin.