Re: Selecting strict, immutable text for a composite type.

Steven Lembark <lembark@wrkhors.com> writes:
> On Thu, 10 May 2018 14:41:26 -0400
> Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Steven Lembark <lembark@wrkhors.com> writes:
>>> The problem is with gists telling me that they cannot index
>>> the type. This works for enums, just not the composite type.  

>> Oh, well, they can't.  There's no GiST opclass covering arbitrary
>> composite types.  This doesn't seem very surprising to me given
>> the lack of operators that such an opclass might accelerate.

> But I thought that they could include functions of composite
> types that were indexable (e.g., text)?

Yeah, but that's not what you did.

I think you could make that work with

exclude using gist (
  lat_lng_text(location) with =,
  effective with &&
)

but it's not going to apply the function without you telling it to.

            regards, tom lane