Re: tablespaces and DB administration - Mailing list pgsql-hackers

From Marty Scholes
Subject Re: tablespaces and DB administration
Date
Msg-id 40B7602D.9090708@outputservices.com
Whole thread Raw
In response to tablespaces and DB administration  (pgsql@mohawksoft.com)
List pgsql-hackers
Josh Berkus wrote:
> The whole point of tablespaces is to> allow placing individual tables and indexes> on seperate volumes.

That was one reason.  I seem to recall several more:

* Putting data on cost appropriate media
Mentioned previously in this thread

* Balancing I/O across spindles
Also mentioned previously, many times

* Inode stability
The free space bitmap never changes during production.  The inode table 
never changes during production (save for last modified and last 
accessed timestamps).  This makes the filesystem VERY likely to be 
functional in case of a crash.  Jounaled file systems have reduced the 
need for this.

* Device independence
Since a tablespace needs only some "file names" and the ability to 
lseek() to any point in a file, a tablespace file can be a file on the 
UFS (or its variantes), a disk partition, or even a tape drive device.



pgsql-hackers by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: Nested xacts: looking for testers and review
Next
From: Philip Warner
Date:
Subject: Re: pg_dump --comment?