Re: BUG #4688: Bug in cache.

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> Oleg wrote:
>> CREATE CAST (tmp_table AS composite_ad_texts)
>> WITHOUT FUNCTION AS ASSIGNMENT;

> "WITHOUT FUNCTION" can only be used when both types are binary
> compatible. You might think that two composite types with the same
> fields are, but they're not: we store the OID of the composite type in
> the records.

Although this qualifies as pilot error (superusers are expected to know
what they're doing), should we attempt to prevent the case? It doesn't
seem like a tremendously unlikely mistake to make, and AFAICS there is
no easy way to recover your data once you've done it.

regards, tom lane