Re: [9.2] Confusion over CacheRegisterSyscacheCallback

Marko Kreen <markokr@gmail.com> writes:
> So my question is that after doing generic SearchSysCache() like:

>    tup = SearchSysCache(USERMAPPINGUSERSERVER,
>         ObjectIdGetDatum(user_mapping->userid),
>         ObjectIdGetDatum(foreign_server->serverid),
>         0, 0);

> what is the proper way to calculate the hashValue that 
> will be given to callback?

Why would you need to know that?  The reason the calculation function
is static is that there's no apparent need to expose that information
outside the syscache subsystem.
        regards, tom lane