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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.
Indexes and index performance considerationsHCL OneDB™ provides several types of indexes. Some performance issues are associated with indexes.
Creating and dropping an index in an online environmentYou can use the CREATE INDEX ONLINE and DROP INDEX ONLINE statements to create and drop an index in an online environment, when the database and its associated tables are continuously available.
Limiting memory allocation while creating indexes onlineThe ONLIDX_MAXMEM configuration parameter limits the amount of memory that is allocated to a single preimage pool and a single updator log pool.

Limiting memory allocation while creating indexes online

The ONLIDX_MAXMEM configuration parameter limits the amount of memory that is allocated to a single preimage pool and a single updator log pool.

The preimage and updator log pools, pimage_<partnum> and ulog_<partnum>, are shared memory pools that are created when a CREATE INDEX ONLINE statement is executed. The pools are freed when the execution of the statement is completed.

The default value of the ONLIDX_MAXMEM configuration parameter is 5120 kilobytes. The minimum value that you can specify is 16 kilobytes; the maximum value is 4294967295 kilobytes.

You can set the ONLIDX_MAXMEM configuration parameter before starting the database server, or you can change it dynamically through the onmode -wf and onmode -wm commands.