RE: exp performance question ( direct=y)

From: Jim Conboy <Jim.Conboy_at_trw.com>
Date: Fri, 22 Jun 2001 12:18:30 -0700
Message-ID: <F001.00334384.20010622122800@fatcity.com>

No, buffer is ignored for
DIRECT=Y. But RECORDLENGTH should be set to DB_BLOCK_SIZE, or a multiple of it. I've had dramatic gains in performance doing this.
Also, pre-8i you couldn't do
direct-mode export of LONG fields. As of sometime in 8i you can (I know it works in 8.1.7).

Jim
>>> MohanR_at_STARS-SMI.com 06/22/01 04:00PM >>>
I dunno. Does the BUFFER still
matter when DIRECT=Y?

If so, I either remove it
entirely, or multiply it by about a factor of five or so.
my $0.02

  <FONT face=Tahoma
  size=2>-----Original Message-----From: JOE TESTA   [mailto:JTESTA_at_longaberger.com]Sent: Friday, June 22, 2001 3:43   PMTo: Multiple recipients of list ORACLE-LSubject: Re:   exp performance question ( direct=y)
  Ron,

  ok i'm now confused,

  exp direct=n|y
  imp no such option
  sql_loader has direct also.

  or am i missing something here?

  joe

>>> RROGERS_at_galottery.org 06/22/01 03:00PM
>>>I thought that DIRECT=Y was for imports only. It makes since
  because in the import you are placing the data directly into the blocks with   out a redo log.I have no idea why there was a difference in the times   unless it was the extra overhead for a command that was not used.ROR   mª¿ªm>>> zlmei_at_hotmail.com 06/22/01 12:55PM
>>>Oracle : 8.0.5Platform : SunCurrently we have
  cron job every night (starting from 11pm) to do export. I changed the   setting "direct" to "y" two days ago while leaving all other parameters   unchanged, hoping to gain some performance. I am a bit surprused to find   that it did not. It actually took longer to create dump file with less   data to export. The whole exp process takes about 2 hours to finish. Yes,   there could be lots of other unix processes running during that time. But   I would still expect to see some improvement because we are doing this way   for quite a while. So my questions are:1. From your "real" export   experience, how much performance boost did you see when you set   "direct=y"?2. If "direct=y" improves the performance, why would anyone   want to use "direct=n"?Thanks.Guang-- here   is my orcle dump file's time stamp:(dmp.1 and dmp.2 are from   direct=y,dmp.3, dmp.4 and dmp.5 are from   direct=n).-rw-rw-r--   1
  mt       prog     1042197132
  Jun 18 01:05 oracle.dmp.5.gz-rw-rw-r--   1   mt       prog     1042375633
  Jun 19 01:04 oracle.dmp.4.gz-rw-rw-r--   1   mt       prog     1042556662
  Jun 20 00:25 oracle.dmp.3.gz-rw-rw-r--   1   mt       prog     1034773279
  Jun 21 01:17 oracle.dmp.2.gz-rw-rw-r--   1   mt       prog     1035237986
  Jun 22 01:22 oracle.dmp.1.gz--here is the parameter   file:BUFFER = 64000COMPRESS = YCONSISTENT = NCONSTRAINTS =

  YDIRECT = YFILE = /oracle/exports/oracle.dmp.pipe#FULL = 
  YGRANTS = YINDEXES = YLOG = /oracle/exports/export.logROWS = 
  YUSERID = xxx/yyyOWNER = 
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