Re: Asynchronous commit - wait or no wait 10GR2

From: Job Miller <jobmiller_at_yahoo.com>
Date: Wed, 3 Oct 2007 05:23:57 -0700 (PDT)
Message-ID: <241629.73989.qm@web53912.mail.re2.yahoo.com>

PL/SQL has always done this "optimization" automatically. so the default within a pl/sql procedure is to commit upon return to the caller. the cwiw setting must override the default pl/sql optimization.

Job

John Hallas <john.hallas_at_bjss.co.uk> wrote: st1\:*{behavior:url(#default#ieooui) } In 10GR2 there is an option to commit immediate nowait which allows the commit to return before the redo is persistent in the redo log. This is not the default. The default commit remains as commit write immediate wait.    

  I am testing Sybase and Oracle inserts and I have noticed an oddity with in Oracle. Solaris 10G T2000 server 10.2.0.3    

  A simple stored procedure    

  create table loaded1 ( id number, name varchar2(8), last_modified date);        

  create or replace procedure sp4 ( loops in number)   as
  cnt number :=0;    

  begin
  while (cnt < loops)

          LOOP
          insert into loaded1 values (cnt,'abcdefgh',sysdate);
          commit write immediate nowait;   XXXXXXXXX
          cnt := cnt+1;
          END LOOP;

  commit;
   end;
  /
  Where line xxxxxxxx can be commit write immediate wait;, commit write immediate nowait; , commit; The first and last should be identical and be the Oracle default. My parameter commit_write is not set. I am truncating the table after each run.    

  Timings    

  CWIW 5000 records 57 secs
  CWINW 5000 records 3 seconds
  Commit 5000 records 3 seconds    

  These figures are repeatable. I think that the first and longest option should be the Oracle default according to all the documentation but I am thinking that in fact the 2nd option (nowait) is the real default.    

  Am I missing something here
   John
+44 (0)113 223 2274 (direct)
+44 (0)113 297 9797
          

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Received on Wed Oct 03 2007 - 07:23:57 CDT