A number of monitoring tables use in-memory buffers (called “pipes”) to collect monitoring data. These parameters control the amount of memory allocated for each pipe:
deadlock pipe max messages
errorlog pipe max messages
sql text pipe max messages
plan text pipe max messages
statement pipe max messages
Adaptive Server can dynamically add memory to a pipe but cannot dynamically remove memory from it, so if you reduce the size of a pipe parameter, you must restart Adaptive Server for the new pipe size to take effect.
These are algorithms for determining the size for the parameters:
For an individual Adaptive Server, the memory required for the each pipe configuration is:
configuration_value x number_of_engines
In a clustered environment, each cluster instance allocates the memory required to create the monitoring table pipes. See “Using monitoring tables in a clustered environment”.
