pg_casts view (was Re: date_trun() with timezones? (was Re: TIME column ...))

Tom Lane escribió:

> However, the interval version of the function can capture the time case
> because there's an implicit cast from time to interval:
>
> regression=# select casttarget::regtype,castcontext,castfunc::regprocedure from pg_cast where castsource =
'time'::regtype;
>        casttarget       | castcontext |                castfunc
> ------------------------+-------------+----------------------------------------
>  interval               | i           | "interval"(time without time zone)
>  time with time zone    | i           | timetz(time without time zone)
>  time without time zone | i           | "time"(time without time zone,integer)
> (3 rows)

BTW it very much looks like we should have a pg_casts view that displays
these things in a human-readable manner (like the above except with
castcontext expanded)

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support