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Current Communication Heap Size


Snapshot Information Level
Application

API Structure(s)
sqlm_appl

Monitor Group
Basic

Resettable

No

 

API Element Name
Element Type

curr_comm_heap_size
information

 

Description:  The current size (in bytes) of the communication heap at the client for the monitored application.

Usage:  You may use this element to understand memory requirements for an application.

This element is returned for compatibility with previous versions of the database system monitor. It will always be set to 0.
Note:The configuration parameters svrioblk and comheapsz only apply to pre-Version 2 clients.

The communication heap is an area of storage from which row-level I/O blocks are allocated for each open remote cursor using blocking. The size of each I/O block is defined by the svrioblk configuration parameter, which is described in the Administration Guide.

For applications connecting to a local database, the value will be zero since these applications do not require the use of a communications protocol to access the database.

If there are many cursors blocking data, the communications heap may become full. When this heap is full, an error is not returned. Instead, no more I/O blocks are allocated for blocking cursors. If cursors are unable to block data, performance can be affected.

If a large number of cursors are unable to block data, you may be able to improve performance by:

Note:This element is measured in bytes, while the configuration parameter allocates the heap in pages that are 4KB in size.

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