Effects of Autoextend and Resize on SAPDBA 
Autoextend
and Resize are two Oracle options for influencing the size of the data files of the database system:- Autoextend
extends the data files automatically by a specified amount
- Resize
lets you increase the size of data files manually (up to the maximum file system size), or reduce their size (down to the largest used block ID of the data file).
These options influence the SAPDBA functions below, and have been adjusted accordingly.
Restore and Recovery
When performing a recovery (that is, importing the offline redo log files), the Oracle database system automatically takes into account the Autoextends made to the data files in a database backup. The consistency checks made on files sizes during and after the database backup, and after the backup, are deactivated.
Database System Check
Parameters for checking freespace in tablespaces that take into account the Autoextend option are the following:
TSP_FULL
for absolute freespace
CRITICAL_SEGS
for critical segments
Reorganization
The preventative freespace check includes the Autoextend option
When you reorganize a tablespace with data files, you can set the Autoextend parameters
MAXSIZE
and
INCREMENT_BY
when you specify the data files. The parameter
MAXSIZE
takes into account the memory of the file system or the raw device.
Tablespace Administration
You can create the data files of the tablespaces with the parameters
AUTOEXTEND ON (OFF)
,
MAXSIZE
and
INCREMENT_BY
. You can also change these parameters. The parameter
MAXSIZE
takes into account the memory of the file system or the raw device.
- You can increase or reduce the size of the data files of the tablespaces with the Resize command. For more information, see
Resizing the Data Files of a Tablespace.