Increase lock hash table size to improve query response time with Adaptive Server 15.5 Cluster Edition.
You may experience delayed query response time with Adaptive Server 15.5 Cluster Edition if the size of the lock hash table is insufficient.
To avoid this, set the value of lock hashtable size using:
lock hashtable size = ( (number of locks * (4 + cluster redundancy level) ) + ( (total data cache size(in KB) / max database page size(in KB)) * (2 + cluster redundancy level) ) ) / 8
If the new value of lock hashtable size is more than the previously configured value, you must also increase the memory configuration of your Adaptive Server by 24 bytes for every byte of increase of lock hash table size.
Note: Adaptive Server may also warn you that allocation of regular Cluster Interprocess Communication (CIPC) messages fails due to lack of message buffers, and to increase the CIPC regular message pool size configuration parameter.
Example 1: Determining the lock hashtable size
If number of locks = 50000, cluster redundancy level = 1, total data cache size = 7000MB, and max database page size = 2KB, set lock hashtable size to:
((50,000 * (4 + 1))+ ((7,000,000/2) * (2+1)))/8 = 1343750.
Example 2: Determining the amount of additional memory
If the previously configured value of lock hashtable size is 1,000 and the newly computed size is 11,000, then increase memory by:
24 * (11,000-1,000) = 240,000 bytes.