Re: Using index for IS NULL query - Mailing list pgsql-performance

Well, you're obviously right - I didn't know this. I guess I've found
that the index is not used for null values, and deduced somehow that
NULL values are not stored in the index.

Thanks, it's nice to find out a 'bug' before it's too late :-)

regards
Tomas

> Are you sure NULL values are not stored? btree, gist and bitmap index
> and search for NULL values.
>
> select amname, amindexnulls, amsearchnulls from pg_am;
>
>  amname | amindexnulls | amsearchnulls
> --------+--------------+---------------
>  btree  | t            | t
>  hash   | f            | f
>  gist   | t            | t
>  gin    | f            | f
>  bitmap | t            | t
> (5 rows)
>
>
> Sincerely yours,
> Vladimir Sitnikov