Snapshot Information Level Application |
API Structure(s) sqlm_appl |
Monitor Group Basic |
Resettable |
No |
|
API Element Name Element Type |
max_comm_heap_size information |
Description: The maximum size (in bytes) of the communication heap at the database client.
Usage: 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.
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 maximum size of the communication heap is defined by the comheapsz configuration parameter, which is described in the Administration Guide.
For applications connecting to a local database, the value of this element will be zero since these applications do not require the use of a communications protocol to access the database.
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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