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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL Informix® database servers.
Performance GuideThe Informix® Performance Guide describes how to configure and operate your HCL Informix® database server to improve overall system throughput and to improve the performance of SQL queries.
Effect of configuration on CPU utilizationThe combination of operating-system and Informix® configuration parameters can affect CPU utilization. You can change the settings of the Informix® configuration parameters that directly affect CPU utilization, and you can adjust the settings for different types of workloads.
Network buffer poolsThe sizes of buffers for TCP/IP connections affect memory and CPU utilization. Sizing these buffers to accommodate a typical request can improve CPU utilization by eliminating the need to break up requests into multiple messages.
Network buffersThe 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.

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.

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