Although table fragmentation is transparent to applications,
as database server administrator you should be aware of how the database
server allocates disk space for table fragments and how the database
server identifies rows in those fragments.
Each table fragment has its own tblspace with
a unique tblspace_id or fragment_id. Disk
Structures for a Fragmented Table shows the disk allocation
for a fragmented table that resides in named fragments of the same
dbspace. Figure 1: Disk
Structures for a Fragmented Table
Attached Indexes
With an attached index, the index and data are fragmented in the same way. You can decide whether
to store the index pages with the corresponding data pages in the same dbspace or store them in
separate dbspaces. For information on choosing a fragmentation strategy, see the HCL OneDB™ Performance
Guide.
Detached Indexes
For
detached indexes, the table fragment and index fragment are stored
in tblspaces in separate dbspaces.
