Re: libpq compression

It seems to be very important to be able to measure network traffic 
between client and server, especially in case of using compression.
Althought there are a lot of toll for monitoring network traffix for 
Linux and other OSes,  I didn't find one which can easily calculate 
traffix for particular backends.
This is why I have added pg_stat_network_traffic view which can be used 
to measure efficiency of protocol message compression for different 
algorithms and workloads.

This is the result of network traffic of two backends one with enabled 
compression and another with disable compression
after execution of "select * from pg_class" command:

select * from pg_stat_network_traffic;
   pid  | rx_raw_bytes | tx_raw_bytes | rx_compressed_bytes | 
tx_compressed_bytes
-------+--------------+--------------+---------------------+---------------------
  22272 |            0 |            0 |                   0 
|                   0
  22274 |            0 |            0 |                   0 
|                   0
  22276 |           29 |        86327 |                  38 
|               10656
  22282 |           73 |        86327 |                   0 
|                   0
  22270 |            0 |            0 |                   0 
|                   0
  22269 |            0 |            0 |                   0 
|                   0
  22271 |            0 |            0 |                   0 
|                   0
(7 rows)


-- 
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company