Re: Improving client/server performance.

There are some sqlnet parameters that you could look at. These include the SDU and TDU parameters
These parameter pairs (NVPairs - Named Value pairs) can be specified in the TNSNAMES.ORA and LISTENER.ORA files.
SDU is the 'Session Data Unit', the size of the packets to send over the network.
The TDU, the 'Transport Data Unit', is the default packet size used within SQL*Net to group data together. Ideally, the TDU parameter should be a multiple of the SDU parameter.

 Practical examples:

• SDU=1024, TDU=1536: SQL*Net will store up to 1536 bytes in a buffer and send this on the network. The lower network layer however will split this packet up into two physical packets of, 1024 and 512 bytes, and send these to its destination. * SDU=1514, TDU=1000: SQL*Net will store up to 1000 bytes and then send these to the lower network layer for distribution. This is a waste of network resources, since the SDU can store an additional 514 bytes per request.

On standard Ethernet networks, the default MTU size is set to 1514 bytes. On standard token ring networks, the default MTU size is 4202.

To specify the SDU and TDU parameters, changes must be made to both TNSNAMES.ORA
and LISTENER.ORA to make these parameters visible.

   TNSNAMES.ORA

     ORCL.WORLD =
           (DESCRIPTION =
                 (SDU=1514)
                 (TDU=1514)
    (ADDRESS =


            (PROTOCOL = TCP)


                  (HOST = fu.bar)
                  (PORT = 1521)
            )
       (CONNECT_DATA = (SID = ORCL))      )

LISTENER.ORA:     SID_LIST_LISTENER =

       (SID_LIST =
         (SID_DESC =


            (SDU = 1514)


            (TDU = 1514)


            (SID_NAME = ORCL)


            (GLOBAL_DBNAME = ORCL.WORLD)         )      )

These parameters can be best used when working with a specific networking environment: Using modem lines, it might be advisble to bring down the SDU and TDU lines, because of the frequent resends, while on fibre or T3 lines, it might be advisable to increase the numbers. The default values for SDU and TDU are 2048, with the maximum value possible being 32768.

If you have access to Oracle's metalink look at doument ID no 44694.1 for a more detailed explanation.

HTH NeilC

screwbai_at_my-deja.com wrote in message <806h3t$s6b$1_at_nnrp1.deja.com>...

>
>
>We are working on improving our performance of our client/server
>application. We are working over a WAN and we have found that we are
>sending small packets across the network. We have identified ARRAYSIZE
>to be one variable that has to be increased in order to increase the
>packetsize and hence performance.
>
>Is there anything else I should look into?
>
>
>Sent via Deja.com http://www.deja.com/

>Before you buy.