However, I know from experience that's not entirely true, (although it's not 
always easy to measure all aspects of your I/O bandwith).

Am I missing something?

Two things I can think of:

Transaction writes are entirely sequential. If you have disks assigned for just this purpose, then the heads will always be in the right spot, and the writes go through more quickly.

A database server process waits until the transaction logs are written and then returns control to the client. The data writes can be done in the background while the client goes on to do other things. Splitting up data and logs mean that there is less chance the disk controller will cause data writes to interfere with log files.

Kind regards,
Andomar


--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

Reply via email to