"Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
>> There is a great deal to be said for
>> ..../database/tablespace/filename
> OK,I seem to have gotten the answer for the question
> Is tablespace defined per PostgreSQL's database ?
Not necessarily --- the tablespace subdirectories could be symlinks
pointing to the same place (assuming you use OIDs or something to keep
the table filenames unique even across databases). This is just an
implementation mechanism; it doesn't foreclose the policy decision
whether tablespaces are database-local or installation-wide.
(OTOH, pathnames like tablespace/database would pretty much force
tablespaces to be installation-wide whether you wanted it that way
or not.)
> My opinion
> 3) database and tablespace are relatively irrelevant.
> I assume PostgreSQL's database would correspond
> to the concept of SCHEMA.
My inclindation is that tablespaces should be installation-wide, but
I'm not completely sold on it. In any case I could see wanting a
permissions mechanism that would only allow some databases to have
tables in a particular tablespace.
We do need to think more about how traditional Postgres databases
fit together with SCHEMA. Maybe we wouldn't even need multiple
databases per installation if we had SCHEMA done right.
regards, tom lane