Question: I have seen your great notes on
network tuning and I saw this notes on recv_buf_size
and send_buf_size in the sqlnet.ora file:
If you are tuning your network to maximize
throughput (as opposed to tuning for fast response time), Oracle
suggests setting recv_buf_size and send_buf_size
sqlnet.ora parameters equal to 3 times the Bandwidth Delay
What is this BDP, and how do I compute the BDP for maximum
Answer: The Oracle TNS has limited ability
to influence the underlying TCP/IP network settings, but there are a
few things that you can do to optimizer your Oracle*Net
these other tips for network tuning.
The bandwidth network product (BDP) starts with the output from a
ping command, issued at your Linux/UNIX or DOS command line prompt::
# ping 123.45.6789
reply from 123.45.6789, bytes 32, time 5ms
reply from 123.45.6789, bytes 32, time 7ms
123.45.6789, bytes 32, time 2ms
reply from 123.45.6789, bytes 32,
They call the BDP a "product" because the value for BDP is indeed
a multiplication of the average round-trip time and the total
bandwidth of the network cable.
For example, if a network has a bandwidth of 100 megabytes per
second and a round trip time of 5 milliseconds, the
recv_buf_size and send_buf_size sqlnet.ora
should be set to a value of at least 63k:
(100X106) * (5X10-3) bits ~= 63k:.
1 byte 5 seconds
---------------- x ------ x --------- = 62,500
8 bits 1000
To prevent network contention, the values for recv_buf_size
and send_buf_size should be set to the maximum amount of
data that might be sent, at least 3x the value of your bandwidth
delay product (BDP).
Also see these important notes for
send_buf_size and recv_buf_size.
Get the Complete
Oracle SQL Tuning Information
The landmark book
SQL Tuning The Definitive Reference" is
filled with valuable information on Oracle SQL Tuning.
This book includes scripts and tools to hypercharge Oracle 11g
performance and you can
for 30% off directly from the publisher.