When installed, the database of the R/3 System has the following initial status:

• Most of the tables and indexes of a tablespace are stored in only one extent.

• Each tablespace consists of exactly one data file.

When data is added to the database, its status changes. The following types of change can occur:

• Additional extents are created for the tables and indexes of a tablespace, to make space for further data.

• When a tablespace is full (there is not enough freespace to create a new extent), additional data files must be added to it.

• Adding extents or deleting complete tables causes freespace fragmentation (external fragmentation) in a tablespace. Free storage space in data files is divided into smaller units.

• An internal fragmentation occurs if the fill level of the database blocks develops differently. The fill level of the individual blocks is initially identical. Creating and deleting data causes some blocks to be filled completely, where as others are relatively empty. As a result, space is used inefficiently.

• If a data record does not fit into a database block, block chaining occurs. The database must then follow a chain from the first block of the data record to the further blocks. As a result, more time is needed for reading data from the disk.

Since the R/3 System usually accesses a table entry using an index, the above changes to the database usually have no negative influence on the time required to access data. However, the changed database status may cause increased run times in connection with full table scans.

A reorganization may have the following effects:

• The data from one object is merged in one extent.

• The data from one tablespace is merged in one or more data files.

• Freespace fragments in an object are merged into larger freespace segments (defragmentation).