sp_helpsegment

sp_helpsegment, when used without an argument, displays information about all of the segments in the database from which you execute it.

For example:
sp_helpsegment 
segment name                          status
------- ----------------------------- ------
       0 system                            0
       1 default                           1
       2 logsegment                        0
       3 seg1                              0
       4 seg2                              0
Specify the segment name as an argument for information about a particular segment. Use quotes when requesting information about the default segment:
sp_helpsegment "default"

This example displays information about seg1:

sp_helpsegment seg1
segment name                           status
------- ------------------------------ ------
      4 seg1                                0

device                 size             free_pages
---------------------- ---------------- -----------
user_data10            15.0MB                  6440
user_data11            15.0MB                  6440
user_data12            15.0MB                  6440

table_name             index_name            indid
---------------------- --------------------- ------
customer               customer                   0

total_size      total_pages free_pages  used_pages
--------------- ----------- ----------- -----------
45.0MB                23040       19320        3720