| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: Import 8.1.6 to 9.2.0.1 weirdness
I'll try the larger buffer and can definitely see how that would make a
difference particularly with tables that don't use LOBs. The Oracle doc
says that for tables containing LOB type columns, rows are inserted
individually. For other tables, the size of the buffer must be large enough
to contain the entire row (but it specifically says "except for LOB and LONG
columns"). It then says that if the buffer
cannot hold the longest row in a table, Import attempts to allocate a larger
buffer.
So I'm wondering, how does it allocate the larger buffer (i.e. how does it determine the appropriate size and is there a way to see that) and how/why should it make a difference on tables using LOB datatypes if it will only do inserts 1 row at a time for those tables anyway?
Also, to answer a few other questions asked:
* there are no errors in the alert log
Thanks for all the responses,
Karen
-----Original Message-----
Sent: Thursday, May 15, 2003 7:37 PM
To: ORACLE-L_at_fatcity.com
Cc: oracledba_at_morton-consulting.com
Importance: High
I don't know if this may have any bearing on the problem you are
experiencing,
but a 64k buffer is rather small. I like to use 10 meg on imports eg.
buffer=10485760
When it is hanging, have you logged in to the target database and checked
to
see what the import session is waiting on via v$session_wait?
Jared
"Karen Morton" <oracledba_at_morton-consulting.com>
Sent by: root_at_fatcity.com
05/15/2003 04:47 PM
Please respond to ORACLE-L
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
cc:
Subject: Import 8.1.6 to 9.2.0.1 weirdness
Would anyone have any idea what might be going on with the following
import
situation?
I'm importing a 8.1.6 database into a 9.2 database. There are almost 400
tables and the import seems to chug along fine until I get to a table with
a
CLOB column in it. At that point, the import loads in anywhere between a
few hundred and a few thousand rows of that table and then "hangs". I end
up having to kill the import session and start over. Actually what has
mostly happened is that I can't even simply restart but end up having to
shutdown the database and restart it before I can continue (don't worry
it's
a new test box so all the ups and downs aren't an issue). Since I'm using
commit=y and the tables involved all have unique keys, I simply have been
restarting the import and letting it take off from there.
Here's my imp command:
imp id/pswd file=exp816.dmp commit=y ignore=y analyze=n buffer=16384
fromuser=user1 touser=user2
I've tried changing the buffer setting from 4K to 64K with no apparent effect. I've also tried various other parameter combinations other than those listed with no help. The command you see is what seems to work best.
The real weird thing is that if I just keep restarting the database and
then
restarting the import, the table will eventually load. For one table that
had 30000 rows, I had to start the import and let it run until it hung,
then
shutdown the database and restart the import 10 times to get the full
table
to load. Once it loads, the import continues on just fine until it hits
another table that has a CLOB datatype. Actually it goes one step further
than just being a table with a CLOB, it's a table with a CLOB that's over
2K
or so. There are a couple of tables with CLOB columns but the max size of
the data stored in that column is relatively small. The tables that seem
to
have troubles have max size in the CLOB column of over 2K.
I just need to get this data loaded for test purposes so I can put up with the process for the moment, but I can't for the life of me figure out why it's acting this way. I've never seen behavior like this.
Does anybody have any ideas/suggestions or think of anything I may be missing somewhere that's causing this problem?
Many thanks,
Karen
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Karen Morton INET: oracledba_at_morton-consulting.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (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.net -- Author: Karen Morton INET: oracledba_at_morton-consulting.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (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).Received on Fri May 16 2003 - 09:51:50 CDT
 |
 |