Peter Eisentraut <peter_e@gmx.net> writes:
> Tom Lane writes:
>> I've been assuming that we would create a separate tablespace for
>> each database, which would be the location of that database's
>> system tables.
> Then I can't put more than one database into a table space? But I can put
> more than one table space into a database?
You can put *user* tables from more than one database into a table space.
The restriction is just on *system* tables.
Admittedly this is a tradeoff. We could avoid it along the lines you
suggest (name table files like DBOID.RELOID.VERSION instead of just
RELOID.VERSION) but is it really worth it? Vadim's concerned about
every byte that has to go into the WAL log, and I think he's got a
good point.
> I think that's the wrong
> hierarchy. More specifically, I think it's wrong that there is a hierarchy
> here at all. Table spaces and databases don't have to know about each
> other in any predefined way.
They don't, at least not at the smgr level. In my view of how this
should work, the smgr *only* knows about tablespaces and tables.
Databases are a higher-level construct.
regards, tom lane