The segmap column is a bitmask linked to the segment column in the user database’s syssegments table. Since the logsegment in each user database is segment 2, and these user databases have their logs on separate devices, segmap contains 4 (22) for the devices named in the log on statement and 3 for the data segment that holds the system segment (20 = 1) + default segment (21 = 2).
Some possible values for segments containing data or logs are:
Value |
Segment |
---|---|
3 |
Data only (system and default segments) |
4 |
Log only |
7 |
Data and log |
Values higher than 7 indicate user-defined segments. The segmap column is explained more fully in the segments tutorial section in Chapter 23, “Creating and Using Segments.”