Search Postgresql Archives

Re: Bitmap Heap scan 8.1/8.2

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Alvaro Herrera wrote:

It's an arbitrary number, based on which all the other numbers are
measured.

Now that I read more intensively he docs I see that all the cost parameters are related one with the other.

What people generally do around here is mess with random_page_cost, and
leave seq_page_cost alone.  Often, it's the ratio
seq_page_cost/random_page_cost what's most important to the cost
equations results.  (seq_page_cost wasn't tunable at all until
recently, say 8.1 or 8.2 AFAIR).

Ok, now the 8.1 server has a RAID1 hardware board with SCSI disks, and the 8.2 is just a PentiumD with SATA disks (it's my desktop PC where I do tests). Should I have a lower random_page_cost on a machine that is likely to have a lower disk IO speed?

--
 21:50:04 up 2 days,  9:07,  0 users,  load average: 0.92, 0.37, 0.18
---------------------------------------------------------
Lic. Martín Marqués         |   SELECT 'mmarques' ||
Centro de Telemática        |       '@' || 'unl.edu.ar';
Universidad Nacional        |   DBA, Programador,
    del Litoral             |   Administrador
---------------------------------------------------------

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux