Indexes help Adaptive Server locate data. They speed data retrieval by pointing to the location of a table column’s data on disk. You can create global indexes and local indexes, each of which can also be clustered or nonclustered.
In clustered indexes, the physical data is stored in the same order as the index, and the bottom level of the index contains the actual data pages. In nonclustered indexes, the physical data is not stored in the same order as the index, and the bottom level of the index contains pointers to the rows on the data pages.
Clustered indexes on semantically partitioned tables are always local indexes—whether or not you specify “local” index in the create index command. Clustered indexes on round-robin tables can be either global or local.
