Re: GIN Expression Indexes

On 4/28/20 1:58 PM, Taylor Sarrafian wrote:
> Hi friends!
>
> We tried to index an array function like this:
>
>   CREATE INDEX my_arr_index ON my_table USING GIN ( my_arr_func( my_col ) )
>
> But the planner can’t seem to figure out how to use the index with any
> query! It doesn’t work with any array operators.
>
>   SELECT * FROM my_table WHERE ARRAY[ 123 ]::INT[] && my_arr_func( my_col )
>
> Even weirder, an empty array correctly uses the index:
>
>   SELECT * FROM my_table WHERE ARRAY[]::INT[] && my_arr_func( my_col )
>
> Is there any way to coerce Postgres into using this index? Thanks!

Well without:

1) Table schema.

2) EXPLAIN ANALYZE for the query(s)

there is really not information to formulate an answer.

>
> ts

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com