Re: MySQL's (false?) claims... (was: Re: PL/java?)

Null asks:

> Would you elaborate on the alternatives that you see to cross-db queries?
>
> Are you saying that it would better to duplicate the same data in several
> databases or put everything in one huge database or what ...?
>
> "Jan Wieck" <JanWieck@Yahoo.com> wrote in message
> news:200108271655.f7RGtG307375@jupiter.us.greatbridge.com...
> >     IMNSVHO the biggest argument against cross-DB queries is this
> >     useless extensibility in  PostgreSQL.   As  soon  as  someone
> >     creates  a data type, operator, aggregate or function, things
> >     get complicated. Have a data type "acctno"  defined  in  both
> >     databases.  And  yes, we have operators for equalness in both
> >     DB's too.  Now we do a cross-DB join and have  two  "acctno"s
> >     in the WHERE clause.
> >
> >     First off, all these objects will have different OID's in the
> >     two system catalogs.  Next, how do you know if the two  types
> >     will  at  least  have  a similar external representation? And
> >     which of the two "=" operator functions will get called?
> >
> >
> > Jan

Really the type isn't just acctno but dbname.acctno

Operators could work by converting both types to some base type
that 'both databases understand'.

Cheers,

Colin