Re: Planner not choosing GIN index

It is an expected behavior. You can see the list of array operators with
which a GIN index can be used in the doc:

https://www.postgresql.org/docs/current/indexes-types.html

And a very good and detailed explanation about any operator here:

https://stackoverflow.com/questions/4058731/can-postgresql-index-array-columns/29245753#29245753

Regards,
Flo

On Wed, Mar 13, 2019 at 2:44 AM Corey Huinker <corey(dot)huinker(at)gmail(dot)com>
wrote:

> A client had an issue with a where that had a where clause something like
> this:
>
> WHERE 123456 = ANY(integer_array_column)
>
>
> I was surprised that this didn't use the pre-existing GIN index on
> integer_array_column, whereas recoding as
>
> WHERE ARRAY[123456] <@ integer_array_column
>
>
> did cause the GIN index to be used. Is this a known/expected behavior? If
> so, is there any logical reason why we couldn't have the planner pick up on
> that?
>