Re: EXPLAIN ANALYZE printing logical and hardware I/O per-node - Mailing list pgsql-hackers

From Gokulakannan Somasundaram
Subject Re: EXPLAIN ANALYZE printing logical and hardware I/O per-node
Date
Msg-id 9362e74e0712142349p32ddc08fm275447f4234181fd@mail.gmail.com
Whole thread Raw
In response to Re: EXPLAIN ANALYZE printing logical and hardware I/O per-node  (Neil Conway <neilc@samurai.com>)
Responses Re: EXPLAIN ANALYZE printing logical and hardware I/O per-node
List pgsql-hackers
Hi,
    I already made a discussion about it. We can view the Logical I/Os. If we enable the log_statement_stats in the conf file and apply the following patch, it is possible. But putting it in Explain analyze makes more sense to me.



*** postgresql-8.3beta1/src/backend/storage/buffer
/bufmgr.c     Tue Sep 25
18:11:48 2007
--- postgresql-8.3patch/src/backend/storage/buffer/bufmgr.c     Fri Oct 19
23:18:36 2007
***************
*** 1470,1477 ****
               localhitrate = (float) LocalBufferHitCount *100.0 / ReadLocalBufferCount;

       appendStringInfo(&str,
!       "!\tShared blocks: %10ld read, %10ld written, buffer hit rate = %.2f%%\n",
!                               ReadBufferCount - BufferHitCount, BufferFlushCount, hitrate);
       appendStringInfo(&str,
       "!\tLocal  blocks: %10ld read, %10ld written, buffer hit rate = %.2f%%\n",
                                        ReadLocalBufferCount - LocalBufferHitCount,
LocalBufferFlushCount, localhitrate);
--- 1470,1477 ----
               localhitrate = (float) LocalBufferHitCount *100.0 / ReadLocalBufferCount;

       appendStringInfo(&str,
!       "!\tShared blocks: %10ld Logical Reads, %10ld Physical Reads, %10ld
written, buffer hit rate = %.2f%%\n",
!                               ReadBufferCount, ReadBufferCount - BufferHitCount,
BufferFlushCount, hitrate);
       appendStringInfo(&str,
       "!\tLocal  blocks: %10ld read, %10ld written, buffer hit rate = %.2f%%\n",
                                        ReadLocalBufferCount - LocalBufferHitCount,
LocalBufferFlushCount, localhitrate);





--
Thanks,
Gokul.
CertoSQL Project,
Allied Solution Group.
(www.alliedgroups.com )

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