Investigating Lock Contention Effects on Performance
Some load or query performance issues result from lock contention. If your kernel
system time is greater than 10%, you may be experiencing lock contention.
To find out if lock contention is affecting performance on your system, do one of
the following:
Run the SAP Sybase IQ monitor with the
-contention option.
On UNIX platforms, run the sar or
vmstat utility.
On Windows platforms, check the CPU usage in the Task Manager.
If you suspect lock contention, you may find it useful to control the level of
partitioning directly by setting:
The -iqpartition server startup option.
The cache_partitions database option.
Note:
Higher than normal kernel system time can also indicate that your kernel is not
well tuned. If this is the case, you may need to adjust kernel parameters;
changing SAP Sybase IQ settings does not fix an
improperly tuned kernel.
(deprecated)-contention
Displays many key buffer cache and memory manager locks. These lock and mutex counters show the activity within the buffer cache and heap memory and how quickly these locks were resolved. Timeout numbers that exceed 20% indicate a problem.