Need help with tuning import????
Date: 1995/05/22
Message-ID: <3pr298$oe8_at_jobe.shell.portal.com>#1/1
Hey all,
Big question for you. I have a table that is about 80 MB in size. IT contains a long raw column. When I export, it does the entire table in just a few minutes. When I import the table it takes 90 minutes. The table contains a long-raw column. Other tables take only minutes to import. So I am assuming it must have something to do with the long raw. But I am confused at this point as to why it takes so long and why it goes through this cyclic behavior of slowing down and speeding up during the import.....
The dynamics of disk i/o are interesting--at the beginning of the import
(about 5 minutes) we write about 350K/sec to both disks (redo logs and
table). Then after about the 5 min mark, the i/o to the disk containing the
table drops to a few K/sec often reaching zero for 20-30 seconds; meanwhile
the i/o to the redo disk continues at the 350K/sec rate. Thereafter
transfer rate for the table's disk goes back up to 350K/sec for a few
seconds then drops back down to near zero. This pattern continues for the
rest of the 80-90 minutes the import takes.
Thanks in advance
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Steve Schow | But you don't need to use the claw, if you
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Received on Mon May 22 1995 - 00:00:00 CEST