rqrioblk - Client I/O block size configuration parameter

This parameter specifies the block size at the Data Server Runtime Client when a blocking cursor is opened.

Configuration type
Database manager
Applies to
  • Database server with remote clients
  • Client
  • Partitioned database server with remote clients
Parameter type
Default [range]
65 535 [4 096 - 65 535 ]
Unit of measure

The memory for blocked cursors is allocated out of the application's private address space, so you should determine the optimal amount of private memory to allocate for each application program. If the Data Server Runtime Client cannot allocate space for a blocking cursor out of an application's private memory, a non-blocking cursor will be opened.

You should also consider the effect of this parameter on the number and potential size of blocking cursors. Large row blocks might yield better performance if the number or size of rows being transferred is large (for example, if the amount of data is greater than 4 096 bytes). However, there is a trade-off in that larger record blocks increase the size of the working set memory for each connection.

Larger record blocks might also cause more fetch requests than are actually required by the application. You can control the number of fetch requests using the OPTIMIZE FOR clause on the SELECT statement in your application.