Progressively slower insert of CLOBs

I am migrating a database to Oracle 8.1.7. First, I have created the tables in Oracle without any indexes (including no primary key). Then, I am using an application that uses JDBC to pull records out of the old database and then insert them (one at a time) into Oracle. This works like a charm except in the case of one somewhat large table
(220,000 records) that contains a CLOB -- other large tables without a
CLOB are fine. The table only has an id and the CLOB. The migration application starts out inserting at a 50 records/second pace; it gets progressively slower such that by less than halfway through it takes a couple seconds per record. I tried restarting the server with _disable_logging=true to no avail. The Oracle server box
(sun-solaris) looks fine in terms of memory (I have 2GB), but CPU is
flatlined near 100%, mostly to user. I feel confident that Oracle is the bottleneck, because once the table had 90,000+ records, I stopped the migration and modified my migration program to simply try to insert a few hardcoded rows and got the same poor performance. I did this after restarting with _disable_logging=true. For good measure, I also did an alter table ... NOLOGGING, though presumable redundant.

Here are various settings from my init<DB>.ora:

db_block_buffers = 175766
shared_pool_size = 479959040
large_pool_size = 15728640
log_buffer = 1638400
_disable_logging=true
java_pool_size = 0
log_checkpoint_interval = 10000
log_checkpoint_timeout = 1800
processes = 50
db_block_size = 8192
sort_area_size = 20971520
sort_area_retained_size = 524288

TIA,
Doug Received on Wed Mar 12 2003 - 22:52:29 CET