Hi, What is the opinion of the list as to the best way of measuring if the following implementation is ok?
http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php As mentioned in earlier mails, this will reduce the per-backend usage of memory by an amount which will be a fraction (single digit percentage) of (NBuffers * int) size. I have done pgbench/dbt2 runs and I do not see any negative impact because of this. Are there any other suggestions for measuring the backend memory footprint? Regards, Nikhils On 2/21/07, Bruce Momjian <[EMAIL PROTECTED]> wrote:
Added to TODO: * Consider decreasing the amount of memory used by PrivateRefCount http://archives.postgresql.org/pgsql-hackers/2006-11/msg00797.php http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php --------------------------------------------------------------------------- Simon Riggs wrote: > On Mon, 2006-11-27 at 14:42 -0500, Bruce Momjian wrote: > > Simon Riggs wrote: > > > int8 still seems like overkjll. When will the ref counts go above 2 on a > > > regular basis? Surely refcount=2 is just chance at the best of times. > > > > > > Refcount -> 2 bits per value, plus a simple overflow list? That would > > > allow 0,1,2 ref counts plus 3 means look in hashtable to find real > > > refcount. > > > > At two bits, would we run into contention for the byte by multiple > > backends? > > No contention, its a private per-backend data structure. That's why we > want to reduce the size of it so badly. > > -- > Simon Riggs > EnterpriseDB http://www.enterprisedb.com > > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
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