Re: Re: Idea: recycle WAL segments, don't delete/recreate 'em

* Bruce Momjian <pgman@candle.pha.pa.us> wrote:

| Most Unix filesystems will not allocate disk blocks until you write in
| them.  If you just seek out past end-of-file, the file pointer is moved
| but the blocks are unallocated.  This is how 'ls' can show a 1gb file
| that only uses 4k of disk space.

Does this imply that we could get a performance gain by preallocating space
for indexes and data itself as well ? I've seen that other database products
have a setup step where you have to specify the size of the database. 

Or does PostgreSQL do any other tricks to prevent fragmentation of data ?


-- 
Gunnar Rønning - gunnar@polygnosis.com
Senior Consultant, Polygnosis AS, http://www.polygnosis.com/