Optimize Fields - Optimize field width and decimal places in multiple tables
With this function you can optimize the fields of multiple tables or themes, i.e. the field width and number of decimal places is reduced to the required minimum (according to the current field values). This mostly reduces the file size of the tables enormously and thus increases the speed to process the data in future.
pressed to select multiple tables or themes).
Common Fields: Shows the fields that occur several times (fields with the same name in the same or in different tables). Click on a field to select or drop the corresponding fields in Unique Fields.
Unique Fields: Shows either the unique fields (option is active) or all fields (option is inactive). Select the fields you want to optimize. See detailed information at Hints to select fields.
Limit Decimal Precision: Activate this option if you want to limit the accuracy of numeric fields:
- You must activate the tables or themes, which you want to optimize, before calling the function (click on them with the mouse pointer - keep the
Additional Places: You can also provide some spare places as a buffer for wider data to come. Enter the number of additional characters that should be added to the required minimum field width (e.g. the area of polygons may increase so the field Area needs 7 instead of 6 places in future).
: Maximum number of decimal places (fields with fewer decimal places stay unchanged).
Click on to optimize the
selected fields. First all records of the table will be analyzed to determine
the maximum field width and the maximum number of decimal places. This may
take some minutes, according to the number of fields and records.
Delete empty field 'name'?: There may be some fields in a table that contain no data. These fields can't be set to a width of 0, but only deleted. Deleting such a field must be confirmed with
. If you click on , all empty fields will be deleted without further inquiry. With
the optimizing can be stopped.
The new fields will be added to the end of the table and all values of the original fields will be copied. This may take some minutes, according to the number of fields and records. To keep the original field order you should either optimize all fields (because all fields will be recreated) or use the function
Reorder Fields afterwards.
The status bar finally shows the number of optimized and the number of empty deleted fields.
- Never Increase Original Field Width:
Activate this option if you want that the field width will never be
increased, only decreased. Deactivate this option if you want to ensure,
that the additional characters are available for all fields (some fields
may increase though).
© 2003 WLM Klosterhuber & Partner OEG