GTW: oracle db link insert taking long time

Hi,

We have a db link in Oracle, which fetch data from SQL server and insert in the Oracle database. It use to insert around 6 million record in about 10 minutes. Bur off late we seem to have performance issues with the db link and it takes about 3 hour to do the same job..

Oracle version 11.2.0.2

I have run the tkprof for a sample insert statement, below is the summary.

call count       cpu elapsed       disk query    current        rows

------- ------  -------- ---------- ---------- ---------- ---------- ----------

Parse 0      0.00 0.00 0          0 0           0

Execute 1      5.31    2003.41 62 1       5908      500000

Fetch 0      0.00 0.00 0          0 0           0

------- ------  -------- ---------- ---------- ---------- ----------  ----------

total 1      5.31 2003.41 62 1       5908      500000

Here is the summary of wait events, most of the time is spent on HS message to agent..