Using a segment to put a table on a specific database device can increase Adaptive Server performance and can give increased control over placement, size, and space usage of database objects. For example:
If you put a table on one device, and its nonclustered indexes on a device on another disk controller, the time required to read or write to the disk can be reduced.
If you put tables and indexes only on specific segments, those objects cannot grow beyond the space available on the devices represented by the segments.
If you put tables and indexes only on specific segments, other objects cannot contend for space with them.
If a large, heavily-used table is split across devices on two separate disk controllers, read and write time may be improved.
Placing a table on a segment
Select the table icon, then select File | Properties.
Select the Space tab.
Select a segment from the Segment list.
Click Apply.