Rejected Block Cursor Requests

Snapshot Information Level
Application

API Structure(s)
sqlm_appl

Monitor Group
Basic

Resettable

No

Event Information Level
Connection

API Structure(s)
sqlm_conn_event

API Element Name
Element Type

rej_curs_blk
counter

Description:  The number of times that a request for an I/O block at the client or server was rejected.

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.

If a large number of cursors were unable to perform data blocking, you may be able to improve performance by:

• Increasing the size of the comheapsz configuration parameter at the client node or server node, depending on which node ran out of space for blocking cursors. For more information about this parameter, see:
  • The database system monitor topic "Maximum Communication Heap Size"
  • The configuration parameter section of the Administration Guide

• Decreasing the size of the svrioblk configuration parameter as described in the configuration parameter section of the Administration Guide

[ Top of Page | Table of Contents | Glossary | Index ]

[ DB2 List of Books | Search the DB2 Books ]