Re: [9.2] Confusion over CacheRegisterSyscacheCallback

On Wed, Mar 07, 2012 at 11:16:06AM -0500, Tom Lane wrote:
> Marko Kreen <markokr@gmail.com> writes:
> > On Tue, Mar 06, 2012 at 04:27:11PM -0500, Tom Lane wrote:
> >> Or you could do like setrefs.c does, and assume you know how to
> >> calculate the hash value for an OID-keyed cache.
> 
> > Ok, the hashoid() hack works.  But please take it as report from
> > the ground that this API is useful outside of core and it would
> > be good if it stays useful.
> 
> Well, you have a point there --- what setrefs.c is doing is already
> pretty grotty, and it would get more so if we added tracking of other
> objects that used non-OID cache keys (though I'm not sure what those
> would be).
> 
> We could expose some macros patterned after SearchSysCacheN that
> take a cache identifier plus the same key values that would be
> needed to search that cache, and return the hash value.  Does that
> seem reasonable?

Yes.

-- 
marko