Re: Array question

On Sep 8, 2009, at 9:10 AM, Andrew Dunstan wrote:

> The protocol doesn't know anything about arrays or composites,  
> AFAIK. If it passes the type oid, it will be the oid of the array or  
> composite type, but the receiver has no way in the protocol of  
> knowing that the type is such an animal. Of course, it is possible  
> to look that up in the catalog (see pg_type columns typtype, typelem  
> and typarray). But, as I pointed out above, none of that helps you  
> determine the info for a type that is user-defined in C.

This explains why the values are hard-coded: we can just identify the  
OIDs. And since hstore and citext are contrib modules, their OIDs are  
not known ahead of time (PostgreSQL does not hard-code them), so one  
would *have* to look them up. :-(

At the very least, we need to find a way to let users tell DBD::Pg how  
to handle certain types. DBD::Pg could then look up the appropriate  
OIDs when it first connects and then store them.

Thoughts?

Best,

David