Thread: start up cost estimate

Hi ,
         I wanted to know , how the start up cost is computed in postgresql . can u give me an example to illustrate the estimation of start up cost .
                                                              thanku raa .

It would be very helpful to have a lot more information.  Some questions that come to mind:

Approximately how many records will you be storing?
How big do you think your biggest tables will be?
How frequently will your biggest tables be accessed (x/day, x/second, x/week)?
Will those accesses be read only, or read/write?
How important is availability vs. cost?
Who is your favorite Irish folk singer?

"rakesh kumar" <trakeshkumar@gmail.com> writes:
>          I wanted to know , how the start up cost is computed in postgresql

Look into
http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/costsize.c

            regards, tom lane

---------- Forwarded message ----------
From: rakesh kumar <trakeshkumar@gmail.com>
Date: Nov 19, 2006 9:31 AM
Subject: Re: [PERFORM] start up cost estimate
To: Joshua Marsh <icub3d@gmail.com>

Hi
                                                  for suppose if I had a query , something like :
      
                       
                      select   o_orderpriority
   
                         from       orders
                              
                          where    o_totalprice < 156163   and exists
                                                                                   (  select   * 
                                                                                     
                                                                                      from     lineitem
                                                                                    
                                                                                     where  l_orderkey = o_orderkey
                                                                                  
                                                                                    and l_extendedprice < 38570
                                                                                    
                                                                                    )