Network buffers

The database server implements a threshold of free network buffers to prevent frequent allocations and deallocations of shared memory for the network buffer pool. This threshold enables the database server to correlate the number of free network buffers with the number of connections that you specify in the NETTYPE configuration parameter.

The database server dynamically allocates network buffers for request messages from clients. After the database server processes client requests, it returns buffers to the network free-buffer pool.

If the number of free buffers is greater than the threshold, the database server returns the memory allocated to buffers over the threshold to the global pool.

The database server uses the following formula to calculate the threshold for the free buffers in the network buffer pool:

free network buffers threshold = 
   100 + (0.7 * number_connections)

The value for number_connections is the total number of connections that you specified in the third field of the NETTYPE entry for the different type of network connections (SOCTCP, IPCSTR, or TLITCP). This formula does not use the NETTYPE entry for shared memory (IPCSHM).

If you do not specify a value in the third field of the NETTYPE parameter, the database server uses the default value of 50 connections for each NETTYPE entry corresponding to the SOCTCP, TLITCP, and IPCSTR protocols.