Re: How does the tsearch configuration get selected?

Teodor Sigaev <teodor(at)sigaev(dot)ru> writes:
>> My guess right now is that we use a GUC that will default if a
>> pg_catalog configuration name matches the lc_ctype locale name, and we
>> have to throw an error if an accessed index creation GUC doesn't match
>> the current GUC.

> Where will index store index creation GUC?

It's not really the index's problem; IIUC the behavior of the gist and
gin index opclasses is not locale-specific. It's the to_tsvector calls
that built the tsvector heap column that have a locale specified or
implicit. We need some way of annotating the heap column about this.

In the case of a functional index you can expose the locale:

create index ... (to_tsvector('english'::regconfig, mytextcol))

but there's still the problem that the planner cannot match that to
a query specified as just WHERE to_tsvector(mytextcol) @@ query.

regards, tom lane