Reference Manual
CHAPTER 4. Database Administration Utilities
With the Compression utility you can compress a database file. The Compression utility reads the given database file and creates a compressed database file. Compressed databases are usually 40 to 60 per cent of their original size. The database server cannot update compressed database files: they must be used in conjunction with write files.
The Compression utility does not compress files other than the main database file.
You can access the Compression utility in the following ways:
From Sybase Central, for interactive use under Windows 95 or NT.
From the system command line, using the dbshrink command-line utility. This is useful for incorporating into batch or command files.
Compressing a database in Sybase Central
To compress a database file:Open the Database Utilities folder in the left panel.
Double-click Compress Database in the right panel. The Compress Database wizard is displayed.
Follow the instructions in the wizard.
For full information on compressing a database in Sybase Central, see the Sybase Central online Help.
The DBSHRINK command-line utilitydbshrink [switches] database-file [compressed-database-file]
dbshrinw [switches] database-file [compressed-database-file]
Switch |
Description |
|---|---|
-q |
Quiet mode—do not print messages |
-y |
Erase an existing output file without confirmation |
dbshrink reads the given database file and creates a compressed database file. The compressed filename defaults to the same name with an extension of cdb. The output filename (with extension) must not be same as the input filename (with extension).
For more information about the command-line switches, see Compression utility options.
Compression utility optionsOperate quietly (-q ) Do not display messages on a window. This option is available only from the command-line utility.
Operate without confirming actions (-y ) Without this option, you are prompted to confirm the replacement of an existing database file.