BUG #5610: Extremely slow bulk insert performance

The following bug has been logged online:

Bug reference:      5610
Logged by:          William Wei
Email address:      william.wei@tsx.com
PostgreSQL version: AS8.4.4
Operating system:   64-bit Linux 2.6.18-164.6.1.el5
Description:        Extremely slow bulk insert performance
Details:

We now experience a significant performance issue on the latest EDB AS 8.4.4
when doing bulk insert/update. The performance is surprisingly poor even
comparing to the first round of testing on EDB AS 8.3.

Generally speaking, bulk insert performance is twice slower in AS8.4.4 than
the performance in EDB AS 8.3 even though we have AS8.4.4 installed on a
much faster server.When using a same pl/sql function to bulk insert 200,000
rows into a partitioned child table directly, the speed is 8092 rows/s on
8.3 while it's 3130 rows/s on 8.4.4. Performance is even worse when using a
C program via ODBC, which is about 7 times slower on 8.4.4 than 8.3.

This is an urgent request. Please respond ASAP. Thanks.