How to perform duplicate detection when your matchcode length is > 450?

Question

I have an entity that has three fields that need to form a unique constraint in my CRM 2011 Organizations, but when I enter them in for a Duplicate Detection Rule, the resulting matchcode length is too long.

At first I was going to just add an odata query in javascript on the form to ensure that no record existed for the unique constraint, but that doesn't catch data import issues.

Is there some way to get around the 450 character limit, or am I most likely going to need to create a plugin?

Answer 1

Using a new field, that contains the values of the 3 fields you want to create the duplicate detection rule, may be an option. You maintain the state of this field with a workflow (on create/update) and apply the duplicate detection rule on it (if the new field does not exceed the limit of the matchcode).

The approach with the plugin may be another choice if the above is not a convenient solution for your scenario.

Answer 2

You can choose to only use part of of one or more of your field eg the first 150 characters - do you really need to be checking the whole of these long fields for absolute uniqueness?

In how many cases would the first 150 characters of each of three fields be identical but not the last bit (which would be the false-positives this causes)?