digoal(at)126(dot)com writes:
> postgres=# create table tbl(id int, t timestamp);
> CREATE TABLE
> postgres=# insert into tbl select 1,now() from generate_series(1,10000);
> INSERT 0 10000
> postgres=# create index idx_tbl_1 on tbl using gin (id,t);
> CREATE INDEX
Apparently you're using contrib/btree_gin, because in the core system
that would just fail. btree_gin lacks any support for cross-type
operators, so it can't index "timestamp > date" comparisons.
regards, tom lane