Re: BUG #5126: convert_to preventing index scan

>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:

 >> convert_to is a builtin function. If there's a bug here, it's that
 >> convert_to is defined as stable rather than immutable. (Sure it
 >> depends on server_encoding, but that can't exactly change... if
 >> there's any other reason why it's not immutable, I can't think
 >> what it is.)

 Tom> The conversion itself is dependent on changeable catalog
 Tom> entries, ie, pg_conversion.  So "stable" seems the appropriate
 Tom> marking to me.

That sounds like a bit of a stretch to me... we treat lots of stuff as
immutable which is actually easier to change than pg_conversion entries
(OS locale definitions for example).

--
Andrew.