Re: index for inet column

Zhihong Yu <zyu(at)yugabyte(dot)com> writes:
> I was able to create gin index on inet column in PG.
> GIN is good with points/elements in sets. Is gin a good index for inet
> column ?

As far as Postgres is concerned, inet is a scalar type: it has a
linear sort order, and there aren't many operations on it that are
concerned with identifiable sub-objects. That means btree is a
perfectly fine index type for it, while GIN (which lives and dies by
sub-objects) is pretty off-point. I suppose you used btree_gin for
your index, because there are no other GIN opclasses that would take
inet. As the name implies, that's a poor man's substitute for btree;
there is nothing it does that btree doesn't do better.

Generally speaking, the use-case for btree_gin is where you want to
make a single, multi-column index in which one column is a collection
type (that is well-suited for GIN) but another is just a scalar type.
If you're making a one-column index with btree_gin, you're doing it
wrong.

> It seems gist index would be better.

Largely the same comments apply to GiST: it's not really meant for
scalar types either.

regards, tom lane