Space Management

This section helps you develop an approach to managing the space of your Oracle database.

You consider whether to use raw devices or a file system. Raw devices are generally 10 to 20% faster on UNIX systems. However, with Oracle direct I/O or Oracle ASM 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.

1. You monitor the database closely:

   • You regularly run the database system check so that you can detect space problems before they become serious.

   • If required, you run these reports on a one-off basis:

     • Showing Tablespaces with BR*Tools

     • Showing Data Files with BR*Tools

     Note

     You also need to monitor available disk space at the operating system level with, for example:

     Showing Disk Volumes with BR*Tools

     Make sure that you plan for additional disk space in time to accommodate data growth.

2. You manage tablespaces to:

   • Extend a tablespace by adding a new file to avoid overflow

   • Create a new tablespace, for example, when switching from a dictionary managed to a locally managed tablespace

   • Rename tablespace, for example, after having reorganized all tables from an old into a new tablespace

   • Drop tablespaces, for example, after an upgrade

3. You manage data files to:

   • Resize the file, usually to prevent overflow

   • Turn on and maintain the Oracle AUTOEXTEND option to avoid data file overflow.

   • Rename data file, for example, to follow SAP naming conventions

   • Move the data file, for example, after you have added new disk storage to your system and want to use it for existing data files.

   • Drop empty data file because it is no longer needed