> Malcolm Matalka <mmatalka@gmail.com> writes: >> Hello, I'm implementing my own pgsql client for fun and I'm trying to >> understand how to send a Parse message. The final parameter to Parse is >> a series of Int32s with the description: >> Specifies the object ID of the parameter data type. Placing a zero here >> is equivalent to leaving the type unspecified. > >> But where do I find the list of object IDs? > > SELECT oid, typname FROM pg_type; > >> If so, It's not clear how to express some things. For example there is >> a MONEYARRAYOID, but no MONEYOID. > > For historical reasons, the macro for money's OID is CASHOID. > There's no grandfathered symbol for money[], though, so that > gets a name constructed per standard rules (cf form_pg_type_symbol > in genbki.pl). > > However, I fail to see why a generic client would need to know that. > If you're hard-wiring OIDs into your code for anything beyond very > basic types like int4, you're probably doing it wrong. Remember
Ok, it wasn't clear to me if and when I should pass this data in. I couldn't find any documentation for this translating to performance improvement, or addressing any possible errors due to ambiguity in types. In general, should an interface no pass that information in on a Parse? Is there a reason to do it?
Yes, if you ever decide to use binary mode for the parameters and the results then you need to know the type