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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.
Administrator's GuideThe HCL OneDB™ Administrator's Guide provides the information required to administer HCL OneDB™.
Disk, memory, and process management
Manage disk spaceYou can use several utilities and tools to manage disk spaces and the data that the database server controls.
Storage optimizationData compression and consolidation processes can minimize the disk space that is used by your data and indexes.Data compression and consolidation processes can minimize the disk space that is used by your data.
CompressionYou can compress and uncompress row data in tables and fragments and simple large objects in dbspaces. You can compress B-tree indexes.You can compress data in tables and table fragments to reduce the amount of disk space. You can also consolidate free space in a table or fragment and you can return this free space to the dbspace. Before you compress data, you can estimate the amount of disk space that you can save.
B-tree index compressionYou can compress detached B-tree indexes. You can also consolidate free space in the index and you can return free space at the end of the index to the dbspace. Before you compress an index, you can estimate the amount of disk space that you can save.

B-tree index compression

You can compress detached B-tree indexes. You can also consolidate free space in the index and you can return free space at the end of the index to the dbspace. Before you compress an index, you can estimate the amount of disk space that you can save.

You can compress a detached B-tree index that is on a fragmented or non-fragmented table.

An index must have at least 2000 keys to be compressed.

You cannot compress the following types of indexes:

An index that is not a B-tree index
An attached B-tree index
Virtual B-tree indexes
An index that does not have at least 2000 keys

The compression operation compresses only the leaves (bottom level) of the index.

You cannot uncompress a compressed index. If you no longer need the compressed index, you can drop the index and then re-create it as an uncompressed index.

You can compress a new index when you create it by including the COMPRESSED option in the CREATE INDEX statement. You compress an existing index with an SQL administration API command.