Managing Tablespaces   «Prev  Next»
Lesson 5 The AUTOEXTEND option
ObjectiveAllow Oracle to resize data files automatically.

AUTOEXTEND option Oracle to resize data files automatically

When you create a data file, you can use the autoextend clause to allow Oracle to resize the file as needed. In doing this, you create tablespaces that grow as their objects grow. The following mouseover describes the syntax of the autoextend clause:
The keyword that marks the beginning of the clause
  1. The keyword that marks the beginning of the clause.
  2. Turns autoextend off. This is the default behavior when you create a new data file.
  3. Specifies the size by which the file will extend each time space is needed. This may be expressed in bytes, kilobytes (K), or megabytes (M).
  4. Allows you to specify a maximum size for the file.
  5. Places no limit on the maximum size.
  6. Specifies an upper limit on file size. This may be expressed in bytes, kilobytes (K), or megabytes (M).

The AUTOEXTEND clause

Autoextend
Autoextend

AUTOEXTEND The keyword that marks the beginning of the clause.
"off" Turns autoextend off. This is the default behavior when you create a new data file.
NEXT nextsize Specifies the size by which the file will extend each time space is needed. This may be expressed in bytes, kilobytes (K), or megabytes (M).
MAXSIZE Allows you to specify a maximum size for the file.
UNLIMITED Places no limit on the maximum size.
maxsize Specifies an upper limit on file size. This may be expressed in bytes, kilobytes (K), or megabytes (M).

The following Slide Show shows how the autoextend clause may be used in the CREATE TABLESPACE, ALTER TABLESPACE, and ALTER DATABASE commands:
Auto Extend 1
1) Auto Extend 1
Auto Extend 2
2) Auto Extend 2
Auto Extend 3
3) Auto Extend 3

The next lesson will teach you how to coalesce fragments within a tablespace into larger, more useable extents of free space.