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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.
Algorithm for determining DS_TOTAL_MEMORYThe database server derives a value for DS_TOTAL_MEMORY if you do not set the DS_TOTAL_MEMORY configuration parameter or if you set this configuration parameter to an inappropriate value.

Algorithm for determining DS_TOTAL_MEMORY

The database server derives a value for DS_TOTAL_MEMORY if you do not set the DS_TOTAL_MEMORY configuration parameter or if you set this configuration parameter to an inappropriate value.

Whenever the database server changes the value that you assigned to DS_TOTAL_MEMORY, it sends the following message to your console:

DS_TOTAL_MEMORY recalculated and changed from old_value Kb
            to new_value Kb

The variable old_value represents the value that you assigned to DS_TOTAL_MEMORY in your configuration file. The variable new_value represents the value that the database server derived.

When you receive the preceding message, you can use the algorithm to investigate what values the database server considers inappropriate. You can then take corrective action based on your investigation.

The following sections document the algorithm that the database server uses to derive the new value for DS_TOTAL_MEMORY.