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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL OneDB™ database servers.
Performance GuideThe HCL OneDB™ Performance Guide describes how to configure and operate your HCL OneDB™ database server to improve overall system throughput and to improve the performance of SQL queries.
Effect of configuration on memory utilizationThe combination of operating-system and HCL OneDB™ configuration parameters can affect memory utilization.
Configuration parameters that affect memory utilizationA large number of configuration parameters in the ONCONFIG file affect memory utilization and performance.
Setting the size of the buffer pool, logical-log buffer, and physical-log bufferThe values that you specify for the BUFFERPOOL, DS_TOTAL_MEMORY, LOGBUFF, and PHYSBUFF configuration parameters depend on the type of applications that you are using (OLTP or DSS) and the page size.
The DS_TOTAL_MEMORY configuration parameter and memory utilizationThe DS_TOTAL_MEMORY configuration parameter places a ceiling on the amount of shared memory that a query can obtain. You can use this parameter to limit the performance impact of large, memory-intensive queries. The higher you set this parameter, the more memory a large query can use, and the less memory is available for processing other queries and transactions.
Deriving a working value for decision-support memoryIn the second part of the algorithm that the database server uses to derive the new value for the DS_TOTAL_MEMORY configuration parameter, the database server establishes a working value for the amount of decision-support memory.
When the DS_TOTAL_MEMORY configuration parameter is setWhen the DS_TOTAL_MEMORY configuration parameter is set, the database server checks whether the SHMTOTAL configuration parameter is set and then determines which formula to use to calculate the amount of decision-support memory.

When the DS_TOTAL_MEMORY configuration parameter is set

When the DS_TOTAL_MEMORY configuration parameter is set, the database server checks whether the SHMTOTAL configuration parameter is set and then determines which formula to use to calculate the amount of decision-support memory.

When SHMTOTAL is set, the database server uses the following formula to calculate the amount of decision-support memory:

IF DS_TOTAL_MEMORY <= SHMTOTAL - nondecision_support_memory THEN
   decision_support_memory = DS_TOTAL_MEMORY
ELSE
    decision_support_memory = SHMTOTAL -
                  nondecision_support_memory

This algorithm effectively prevents you from setting DS_TOTAL_MEMORY to values that the database server cannot possibly allocate to decision-support memory.

When SHMTOTAL is not set, the database server sets decision-support memory equal to the value that you specified in DS_TOTAL_MEMORY.