Developer’s Guide

14 FileMaker Developer’s Guide
Using the File Maintenance feature
Use the File Maintenance feature to improve the performance of
your database files. The Compact File option removes free disk
space from a file, reducing the file size and streamlining data access.
The Optimize File option improves file access speed by moving
logically related data closer together. Both features reduce disk-head
movement. Improvements will be especially noticeable when you
are using large files and performing finds or sorts, or executing
scripts that operate on all records.
The Compact File option compresses the file by removing free space,
combining partially full disk pages and eliminating gaps in the data.
This feature is useful in reducing the size of a database file. If there
is going to be more data added to the file, you might not want to use
the Compact File feature, as it will increase the amount of
fragmentation occurring when new data is written to the database in
the future. If you do add data to a file that has been compacted, you
can defragment it with the Optimize File feature.
The Optimize File option defragments the file to make the physical
arrangement of data match the logical arrangement. This feature is
especially useful for increasing the speed at which finds and sorts are
performed on files with a large number of records. You can use the
Optimize File feature at any time, even on databases that will have
data added to them.
Both File Maintenance options work on the currently open database
file, without creating another copy. If you are hosting files,
networked clients will not have access to the file maintenance
features for those files.
You can use the options together or by themselves. You can cancel
the operation of the features at any time with the compression and
defragmentation that has been performed up to the point of
cancellation still retained.
1. Open a database file.
2. Choose File menu > File Maintenance.
3. Select one or both options, then click OK.
A File Maintenance Status dialog box shows you the progress of the
features. An alert dialog box tells you when file maintenance is
complete.
Using custom functions
Use the Custom Functions feature to create custom functions that can
be reused anywhere in the database file in which they are created.
Once formulas are written for the function, they don’t have to be
rewritten to be applied to other fields or used in other scripts.
You can maintain and edit custom functions and the formulas they
contain in one central location. Any change made to the custom
function will be copied to all instances where that custom function
has been used.
1 Any users of the database file that contains a custom function can
use the function if they have the proper permissions.
1 Custom functions will run in both FileMaker Pro and FileMaker
Developer, and across multiple platforms.
1 Newly defined functions appear under their own category in the
functions list of the Specify Calculation and Define Custom
Functions dialog boxes.
1 If you do not wish to reveal your custom functions, you can disable
the display of them in these dialog boxes.
File Maintenance dialog box