Contents Index Deleting a dbspace Working with write files

ASA Database Administration Guide
  Working with Database Files
    Using additional dbspaces

Pre-allocating space for database files


Adaptive Server Anywhere automatically grows database files as needed. Rapidly changing database files can lead to excessive file fragmentation on the disk, resulting in potential performance problems. Unless you are working with a database with a high rate of change, you do not need to worry about explicitly allocating space for database files. If you are working with a database with a high rate of change, you may pre-allocate disk space for dbspaces or for transaction logs using either Sybase Central or the ALTER DBSPACE statement.

You must have DBA authority to alter the properties of a database file.

Performance Tip  
Running a disk defragmentation utility after pre-allocating disk space helps ensure that the database file is not fragmented over many disjoint areas of the disk drive. Performance can suffer if there is excessive fragmentation of database files.

To pre-allocate space (Sybase Central)

  1. Open the Dbspaces folder.

  2. Right-click the desired dbspace and choose Pre-allocate Space from the popup menu.

  3. Enter the number of pages to add to the dbspace and click OK.

To pre-allocate space (SQL)

  1. Connect to a database.

  2. Execute an ALTER DBSPACE statement.

Example 

Increase the size of the SYSTEM dbspace by 200 pages.

ALTER DBSPACE system
ADD 200
Example 

Increase the size of the SYSTEM dbspace by 400 megabytes.

ALTER DBSPACE system
ADD 400 MB

See also


Contents Index Deleting a dbspace Working with write files