Message-Id: <25956.338501@fatcity.com> From: "Rich Holland" Date: Fri, 18 Jul 2003 15:08:32 -0400 Subject: RE: Export direct=Y|N I don't know the answer for sure, but can hazard a guess. :-) 65535 is typically the maximum number of bytes that can be written with a single write() system call. If you use a shorter record length, you'll execute multiple write()'s for each 64K of data, which involves multiple trips through kernel land. If you use larger values, you're not buying anything unless it's a multiple of 65535; i.e. if you specify 65536 you'll be back to 2 writes per chunk. Specifying 2x65535 will require the same two writes, and gets 65534 more bytes transferred than the previous example! It's a very small incremental time, but over the course of a 20G export all those round trips between kernel and user space can really add up.... -- Rich Holland (913) 645-1950 SAP Technical Consultant print unpack("u","92G5S\=\"!A;F]T:&5R(\'!E . about to export SYSTEM's tables via Direct Path ... > EXP-00067: Table DEF$_AQCALL will be exported in conventional path. 24a26 > EXP-00067: Table DEF$_AQERROR will be exported in conventional path. 29a32 > EXP-00067: Table DEF$_LOB will be exported in conventional path. 33a37 > EXP-00067: Table DEF$_TEMP$LOB will be exported in conventional path. 127c131 < . about to export OUTLN's tables via Conventional Path ... --- > . about to export OUTLN's tables via Direct Path ... 130,136c134,140 < . about to export DBSNMP's tables via Conventional Path ... < . about to export OPS$ORACLE's tables via Conventional Path ... < . about to export CW30_AUDITOR97's tables via Conventional Path ... < . about to export CW30_LAC_MANUAL's tables via Conventional Path ... < . about to export DISPUTES2's tables via Conventional Path ... < . about to export DISPUTES3's tables via Conventional Path ... < . about to export BANK's tables via Conventional Path ... --- > . about to export DBSNMP's tables via Direct Path ... > . about to export OPS$ORACLE's tables via Direct Path ... > . about to export CW30_AUDITOR97's tables via Direct Path ... > . about to export CW30_LAC_MANUAL's tables via Direct Path ... > . about to export DISPUTES2's tables via Direct Path ... > . about to export DISPUTES3's tables via Direct Path ...