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?