[Migrated content. Thread originally posted on 23 May 2004]
We use the WHERE constraint in our application to provide upper boundaries when doing a start in the file operations. This works fine when we know the scope of the records that need to be processed. (e.g. when we need to find all records that have an ID of 555555555, we can supply an upper boundary of greater than the ID, and it treats any record greater as an invalid key)But when we don't know the scope of the data to be processed, we haven't found a way to use the WHERE constraint. For example, give me the first 50 records in a file for a listbox. We can't figure out a way to use a WHERE constraint to provide an upper boundary.
Has anyone else encountered this problem using Acu4GL, and found a trick to use to provide a constraint to minimize the file i/o? Some of these files have 50-500K records, so narrowing the scope is very important to us.