Space Management 
Purpose
This section helps you develop an approach to managing the space of your Oracle database.
Process Flow
You consider whether to use raw devices or a file system. Raw devices are generally 10 to 20% faster on UNIX systems. However, with Veritas Quick I/O the difference is reduced.
We recommend raw devices only for experienced database administrators because the administration is more complex. For example, only one Oracle file can be set up on each raw device.
You use the Oracle AUTOEXTEND option, recommended starting with Oracle Release 8. AUTOEXTEND means that tablespaces are automatically extended when they run out of space.
We recommend using this when you:
Create a new tablespace
Extend an existing tablespace by adding a new file
Resize the existing data files of a tablespace
For more information on AUTOEXTEND, see the Oracle documentation.
- You set up locally managed tablespaces when creating new tablespaces and during a reorganization, except for system and rollback tablespaces.
For more information on our recommendations for locally managed tablespaces, see SAP Note 416772.
- You check the database system regularly, so that you can identify potential problems in space management early.
- If you identify a problem with the tablespaces, you perform tablespace administration.
- If you identify a problem that might require reorganization, you consider the following:
- Indexes can often become unbalanced, requiring reorganization. However, this does not occur with locally managed tablespaces, because fragmentation is no longer possible.
- Reorganization is necessary if you switch from normally (that is, dictionary-) managed to locally managed tablespaces.
- Fragmentation is often a reason for reorganization:
- Internal fragmentation: fragmentation of table or index data within a block or chaining of data over several blocks
- External fragmentation: fragmentation of the extents of a logical object and of the free space within a tablespace, maximum number of extents for an object reached
For more information if you decide to reorganize, see Reorganization.