Re: Re: equal operator for _int4 (array of int4)

Oleg Bartunov <oleg@sai.msu.su> writes:
> What will happens if we ignore NULLs ?

Same thing that happens with hash:

regression=# create table foo (f1 int);
CREATE
regression=# create index fooi on foo using hash (f1);
CREATE
regression=# insert into foo values(1);
INSERT 292677 1
regression=# insert into foo values(null);
INSERT 292678 1
regression=# vacuum foo;
NOTICE:  Index fooi: NUMBER OF INDEX' TUPLES (1) IS NOT THE SAME AS HEAP' (2).       Recreate the index.
VACUUM

> We need to provide vacuum some information about numbers of NULL values.

Preferably without hardwiring assumptions about the behavior of
different index types into VACUUM.

That cross-check in VACUUM has really caused way more grief than it's
worth.  I'm beginning to wonder if we should just take it out...
        regards, tom lane