On Tue, Sep 21, 2010 at 11:49 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> I think it would be useful to have a way of testing whether a cast to >> a given type will succeed. The biggest problem with the >> exception-catching method is not that it requires writing a function >> (which, IMHO, is no big deal) but that exception handling is pretty >> slow and inefficient. You end up doing things like... write a regexp >> to see whether the data is in approximately the right format and then >> if it is try the cast inside an exception block. Yuck. > > The problem here is that putting the exception handling in C doesn't > make things any better: it's still slow and inefficient. And in the > general case the only way to be sure that a string will be accepted by > the input function is to try it.
Given the current API, that is true. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
