Using the Set File Attributes Command

The Set File Attributes command from the Operation menu specifies the initial file size and the extent of file growth for selected database files, which preallocates database files at the expected maximum file size. Pre‑allocation provides the opportunity to mitigate the usual overheads, including file system fragmentation (since files can be defragmented prior to use).

As database files grow in small variable increments on demand, and the gradual growth incurs both a direct I/O performance penalty and an indirect performance penalty due to disk fragmentation, use the Set File Attributes command to tailor the amount by which your database files grow.

To set database file attributes

Select the Set File Attributes command from the Operation menu. The Select Files for File Attribute Changes dialog, shown in the following image, is then displayed.
If you do not want the database files in the Database Files list box at the left of the dialog sorted by file number (the default), select the Sort by file name or the Sort by file directory and name item in the Sort by drop‑down list box.
Select the required database file or files for certification, by performing one of the following actions.
- Select the files from the Database Files list box. The selected files are highlighted. When you have selected all of the files that you require, click the Add button.
- To select all of the database files, click the Add All button.
- Select each file by double-clicking the file in the Database Files list box.
The selected files are then moved to the Selected files list box at the right of the dialog.
To remove database files from the Selected files list box, perform one of the following actions.
- Select the files for removal from the Selected files list box. When you have selected all of the files for removal, click the Remove button.
- To remove all of the files from the Selected files list box, click the Remove All button.
- Select each file by double-clicking the file in the Selected files list box.
The selected file names are moved back to the Database Files list box at the left of the dialog.
Click the Set to default button, to restore the initial size and the growth extent increment size for all files displayed in the Selected files list box to the default values specified by the DefFileGrowthIncrement and DefInitialFileSize parameters in the [PersistentDb] section of the JADE initialization file.
In the Initial Size text box, specify the number of bytes that you require for the initial size of the files displayed in the Selected files list box. Set this value explicitly (for example, 16384) or by using a prefix multiplier (for example, 16K).

The default value is 16K and the minimum value is 4K.
In the Extent Size text box, specify the number of bytes that you require for the growth increment extent of the files displayed in the Selected files list box. Set this value explicitly (for example, 16384) or by using a prefix multiplier (for example, 16K).

The default value is 64K and the minimum value is 4K.
When your list of selected files is complete, click the OK button to start the operation. Alternatively, click the Cancel button to abandon your selections.

While the operation is running, a progress dialog is displayed that enables you to monitor the progress of the operation. You can abort the run, by clicking the Cancel button.

When the operation is finished, the progress dialog is closed and the following message is displayed in the running report.

<<File size changes completed>>