Creating and Using Segments

A segment is a label that points to one or more database devices.

Segment names are used in create table and create index commands to place tables or indexes on specific database devices. Using segments can improve SAP ASE performance and give the system administrator or database owner increased control over the placement, size, and space usage of database objects.

Create segments within a database to describe the database devices that are allocated to the database. Each SAP ASE database can contain up to 32 segments, including the system-defined segments. Before assigning segment names, you must initialize the database devices with disk init and then make them available to the database with create database or alter database.

See Performance and Tuning Series: Physical Database Tuning > Controlling Physical Data Placement for information about how segments can improve system performance.