Re: Big 7.1 open items - Mailing list pgsql-hackers

From Hiroshi Inoue
Subject Re: Big 7.1 open items
Date
Msg-id 395A8FDF.1132EC6D@tpf.co.jp
Whole thread Raw
In response to RE: Big 7.1 open items  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
List pgsql-hackers
Tom Lane wrote:

> "Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
> > Why do we have to have system tables per *database* ?
> > Is there anything wrong with global system tables ?
> > And how about adding dbid to pg_class,pg_proc etc ?
>
> We could, but I think I'd vote against it on two grounds:
>
> 1. Reliability.  If something corrupts pg_class, do you want to
> lose your whole installation, or just one database?
>
> 2. Increased locking overhead/loss of concurrency.  Currently, there
> is very little lock contention between backends running in different
> databases.  A shared pg_class will be a single point of locking (as
> well as a single point of failure) for the whole installation.

Isn't current design of PG's *database* for dropdb using "rm -rf"
rather than for above 1.2. ?
If we couldn't rely on our db itself and our locking mechanism is
poor,we could start different postmasters for different *database*s.


> It would solve the DROP DATABASE problem kind of nicely, but really
> it'd just be downgrading DROP DATABASE to a DROP SCHEMA operation...
>

What is our *DATABASE* ?
Is it clear to all people ?
At least it's a vague concept for me.
Could you please tell me what kind of objects are our *DATABASE*
objects but could not be schema objects ?

Regards.

Hiroshi Inoue




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