Re: tablespaces in 7.5?

That's right it's a big one from a performance and admin perspective. DB2, Oracle and Informix have tablespaces. It appears that it has been in the postgres crosshair for a few years now. I'm not sure how much has been completed so far.

Few scenarios where they are really important:

1.
Right now a database can be as fast as one disk. Tablespaces allow you to distribute database objects across multiple physical locations. A big index or table can live on separate disks distributing the io activity.

2.
Say you are close to running out of disk space and want to grow some of the data onto another disk. Table spaces allow you to alter the table space and more easily move the big table or indexes onto a different disk rather than just moving the entire db to a bigger single disk.

3.
Say there is a part of a database that you want to backup every hour, but backing up entire database is overkill. You can set it up so it backs up different table spaces at different times.

4.
Couple other features of tablespaces are that they allow you to allocate space to a specific tablespace and to take only part of a database offline or online very easily.

More detail on what they are how to mange them with oracle...
http://www.engin.umich.edu/caen/wls/software/oracle/server.901/a88856/c04space.htm

http://www.siue.edu/~dbock/cmis565/ch8-tablespaces.htm
http://www-rohan.sdsu.edu/doc/oracle/server803/A54641_01/ch8.htm

-----Original Message-----
From: John Sidney-Woollett [mailto:johnsw(at)wardbrook(dot)com]
Sent: Sat 12/13/2003 4:38 AM
To: Keith C. Perry
Cc: Bruce Momjian; Brian Maguire; pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] tablespaces in 7.5?

My (limited) understanding is that it will give you the ability to:

i) decide what data resides in what tablespace, (database, schema,
indexes, data [coarser -> finer grain]).
ii) where the tablespace data is physically located, allowing you to
distribute your database across disks, or disk arrays.

John Sidney-Woollett

Keith C. Perry said:
> Quoting Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>:
>
>> Brian Maguire wrote:
>> > I am curious if tablespaces are going to be seriously targeted
>> > for the next version. It really opens up new levels of scalability
>> > and is a killer feature from an administration perspective.
>>
>> I hope so!
>>
>> --
>> Bruce Momjian | http://candle.pha.pa.us
>> pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
>> + If your life is a hard drive, | 13 Roberts Road
>> + Christ can be your backup. | Newtown Square, Pennsylvania
>> 19073
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>
> Excuse my ignorance but what will namespaces give us? I though PG schema
> provided the namespace functionality- 'least the way I am understanding
> the term.
>
> --
> Keith C. Perry, MS E.E.
> Director of Networks & Applications
> VCSN, Inc.
> http://vcsn.com
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