RE: exp performance question ( direct=y)

[Yosi]

I believe so. It may have a slightly different meaning.  Rows, commit, these things act a little differently. (Is that not specific enough?)  And direct is an exp param, that greatly affects your imp.   Statistics is another exp parameter that takes affect on import. The export puts a stats statement in the dump file, which imp finds and executes. I imagine direct works the same way.   A quick test on a tiny table shows that conventional exp creates a dump file that's slightly bigger. Visually, in a text editor, both files look very much alike.   And the timing difference - for the export - was BIG. The conventional exported in 12 seconds, the direct was INSTANT, less than a second.   I've experienced the same on large tables, and I probably even have timings saved somewhere.   HTH,   Yosi      -----Original Message----- From: Mohan, Ross [mailto:[EMAIL PROTECTED]] Sent: Friday, June 22, 2001 4:01 PM To: Multiple recipients of list ORACLE-L Subject: RE: exp performance question ( direct=y) 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 -----Original Message----- From: JOE TESTA [mailto:[EMAIL PROTECTED]] Sent: Friday, June 22, 2001 3:43 PM To: Multiple recipients of list ORACLE-L Subject: 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   >>> [EMAIL PROTECTED] 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 m���m >>> [EMAIL PROTECTED] 06/22/01 12:55PM >>> Oracle : 8.0.5 Platform : Sun Currently 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 = 64000 COMPRESS = Y CONSISTENT = N CONSTRAINTS = Y DIRECT = Y FILE = /oracle/exports/oracle.dmp.pipe #FULL = Y GRANTS = Y INDEXES = Y LOG = /oracle/exports/export.log ROWS = Y USERID = xxx/yyy OWNER = (aaa,bbb) _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Guang Mei   INET: [EMAIL PROTECTED] Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051 San Diego, California        -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from).  You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Ron Rogers   INET: [EMAIL PROTECTED] Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051 San Diego, California        -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from).  You may also send the HELP command for other information (like subscribing).