Automatic Segment Space Management 
Definition
This submonitor in the SAP/Oracle Database Monitor lets you check the automatic segment space management (ASSM) of the database. You can see:
· Tablespaces with ASSM
· All Tablespaces
· Tables with ASSM
· Tables without ASSM
ASSM simplifies and blocks the storage of tables and indexes by replacing linked-list freelists with bitmap freelists, which are faster and more efficient. ASSM reduces buffer busy waits.
Use
You choose Detailed Analyses ® Overall activity ® Automatic Space Management and the required tab page.
You cannot view history information in this monitor.
In Tables with ASSM and Tables without ASSM, output is limited to the first 50 tables. Choose Select Table to display information from a table of your choice.
Structure
Entries marked “RAC only” appear only for Oracle Real Application Cluster (RAC)
· Tablespaces with ASSM
This tab page displays information on tablespaces with ASSM:
Column |
Description |
Name |
Name of tablespace |
Block Size |
Tablespace blocksize |
Status |
Tablespace status. For example, ONLINE, OFFLINE, INVALID. |
Contents |
Type of tablespace: TEMPORARY for dedicated temporary tablespaces or PERMANENT for tablespaces that can store both temporary sort segments and permanent objects. |
Extent Management |
Extent management, LOCAL or DICTIONARY |
Allocation Type |
Allocation type, USER, SYSTEM or UNIFORM |
Segment Space Mngt |
Segment space management, AUTO |
· All Tablespaces
This tab page shows the same information as in the table above, but includes tablespaces with and without ASSM:
¡ With ASSM: Segment Space Mngt is AUTO
¡ Without ASSM: Segment Space Mngt is MANUAL
· Tables with ASSM
This tab page displays information on tablespaces with ASSM:
Column |
Description |
Table Name |
Name of table |
Tablespace Name |
Name of tablespace |
Used Space (Bytes) |
Used space in the table in bytes |
Unused Space (Bytes) |
Unused space in the table in bytes |
Meta Data Blocks |
Total blocks reported by DBA_TABLES minus sum of values reported by PL/SQL routine SPACE_USAGE |
Choose Select Table to display information on a selected single table or a group of tables.
· Tables without ASSM
This tab page shows the same information as in the table above, but includes tables with and without ASSM.