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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
Data storageThe database server uses physical units of storage to allocate disk space. It stores data in logical units. Unlike the logical units of storage whose size fluctuates, each of the physical units has a fixed or assigned size that is determined by the disk architecture.
TblspacesDatabase server administrators sometimes must track disk use by a particular table. A tblspace contains all the disk space allocated to a given table or table fragment (if the table is fragmented). A separate tblspace contains the disk space allocated for the associated index.
Extent interleavingThe database server allocates the pages that belong to a tblspace as extents. Although the pages within an extent are contiguous, extents might be scattered throughout the dbspace where the table is located (even on different chunks).

Extent interleaving

The database server allocates the pages that belong to a tblspace as extents. Although the pages within an extent are contiguous, extents might be scattered throughout the dbspace where the table is located (even on different chunks).

The following figure depicts this situation with two noncontiguous extents that belong to the tblspace for table_1 and a third extent that belongs to the tblspace for table_2. A table_2 extent is located between the first table_1 extent and the second table_1 extent. When this situation occurs, the extents are interleaved. Because sequential access searches across table_1 require the disk head to seek across the table_2 extent, performance is worse than if the table_1 extents were contiguous. For instructions on how to avoid and eliminate interleaving extents, see your HCL OneDB™ Performance Guide.

\The paragraph that precedes this figure describes the content of the figure. — Figure 1: Three extents that belong to two different tblspaces in a single dbspace