Why would an Insert /*+ append */ be slower than a straight insert?

Here is the situation. Im testing a load process and I need to show results between the old method and a newer method to management.

Here are the details.
I did an

Insert /*+ append */ into Master
select * from stage;

Also did it without append and the regular insert was about 40% faster. Here are the details.

Oracle 8.1.7
Solaris v5.8
Each table in a seperate tablespace
Same I/O device for everything
Both tablespaces are taken offline to flush the DB_BUFFER_CACHE ALTER SYSTEM FLUSH SHARED_POOL; issued as well. 2.5m rows inserted.
Master table is truncated between loads
There is a primary key with 7 columns that is enabled(yes I know append is faster with disabled, but Im testing all possibilities) Both TABLESPACSE are set to NOLOGGING
Both Tables are set to NOLOGGING.
Only one session is active on the server. Nothing else is going on

any ideas? Id assume at worst Append would be the same speed? Received on Thu May 22 2003 - 14:45:55 CDT