Space Areas (SAP DB) (SAP Library

Space Areas (SAP DB)

Overview of the use of database space.

Data Area

This provides information about the current database fill level.

This area contains the following information:

Total data area size
Size of the data area used by permanent and temporary data pages
Total free data area
Number of data pages changed since the last data backup. This provides you with the number of data pages an incremental backup would include at this point.

Log Area

This provides information about the status of the database log and the number of savepoints and checkpoints written since the database was installed.

This area contains the following information:

Log mode
Total log area size
Log segment size
Reserved area for REDO operations in the data area
Size of the log area used that is not backed up
Total free log area

If more than 60% is used, backup the log segments to free up space for additional transactions. To automate this process, activate automatic log backup.

Log mode	Explanation
Demo	When log reaches a certain size, log will be overwritten (not recommended for production systems).
Single	Log segments are backed up
Dual	Log segments are backed up and mirrored (recommended for production systems)

The reserved data area is used during a database restore for loading log entries. Besides this use, the area can only be used by temporary data pages.

Caches

Displays size of most important caches (data, converter, catalog, and rollback caches) as well as successful accesses and the cache hit rate for all caches. This provides you with an overview of the general cache efficiency on your database server. In a balanced system, the hit rate for the data and converter caches should be above 98%; for the catalog cache, above 90%. The lower the hit rate the less efficient the database system.