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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.
Configure and monitor memory cachesThe database server uses caches to store information in memory instead of performing a disk read or another operation to obtain the information. These memory caches improve performance for multiple queries that access the same tables. You can set some configuration parameters to increase the effectiveness of each cache. You can view information about memory caches by running onstat commands.
Monitor and tune the SQL statement cacheThe SQL statement cache stores optimized SQL statements so that multiple users who run the same SQL statement can achieve some performance improvements.
Monitoring and tuning the size of the SQL statement cacheIf the size of the SQL statement cache is too small, performance problems can occur. You can monitor the effectiveness of the size of the SQL statement cache.
Too many single-use queries in the SQL statement cacheWhen the database server places many queries that are only used once in the cache, they might replace statements that other applications use often. You can view onstat -g ssc all output to determine if too many unshared SQL statements occupy the cache. If so, you can prevent unshared SQL statements from being fully cached.

Too many single-use queries in the SQL statement cache

When the database server places many queries that are only used once in the cache, they might replace statements that other applications use often. You can view onstat -g ssc all output to determine if too many unshared SQL statements occupy the cache. If so, you can prevent unshared SQL statements from being fully cached.

Look at the values in the following output columns in the

Statement
Cache Entries

portion of the onstat -g ssc all output. If you see a lot of entries that have both of the following values, too many unshared SQL statements occupy the cache:

flags column value of F in the second position
A value of F in the second position indicates that the statement is currently fully cached.
hits column value of 0 or 1
The hits column shows the number of times the SQL statement has been executed, excluding the first time it is inserted into the cache.

Increase the value of the STMT_CACHE_HITS configuration parameter to prevent unshared SQL statements from being fully cached.