In Microsoft Dynamics CRM 2011, I want to create a duplicate rule that consists of several fields. However, when I try to save the rule it shows an error that says that the total length of the duplicate rule is too large (maximum is 450). How do I get around this problem?
Well, first of all you can't get around the limit of 450 characters. Your only option is thus to define your duplicate rule to be within the limit. First, you should ensure that there aren't any fields in the duplicate rule that aren't strictly necessary. If you have removed these and you still exceed the maximum length, there is a trick that you can apply.
Some of the CRM fields have very large lengths. For some fields, this maximum length will probably never be reached. The trick is to change the duplicate rule from being an exact match to one that only checks the first X characters. Now, only the X characters will count towards the duplicate rule length and you thus have reduced the length.
An example field where you might be able to apply this trick is the zipcode field, which has a length of 21 characters. By default, including this field as an exact match in your duplicate rule would add 21 to the length of the duplicate rule. However, most countries use zipcodes with far less characters. In our system, zipcodes are always defined using 7 characters, never more. We thus can safely change its duplicate field match rule to only match on the first 7 characters, thereby reducing the overall duplicate rule length by 14 characters.