If you have too many datasets in your tables, queries or forms, it is possible to reduce them by temporarily setting a filter. The definition of the filter will not be saved. To use it you have to perform two steps
define the filter
activate the filter
To define a filter, press the filter definition button and enter a conditional statement. It has the same syntax as the "WHERE" syntax of SQL-statements.
After you have closed the dialog, the filter activation button is enabled. Press it to activate the filter, press it again to deactivate the filter.