As it turns out, database performance issues can easily be created by overdoing the forms. As such, I was just reviewing the SQL Server recommendations, and I found the following interesting fact: with CRM you have roughly 8060 bytes available to store custom fields before theoretically degrading performance.

The following list of data types and size should help in determining if you go over or not. As a note, usually SQL will handle gracefully the overflow.

Data Type Size (bytes)
Lookup 16 bytes
Single Line Text (x length) 2x bytes
Multi Line Text (x length) 2x bytes
Date and Time 8 bytes
Decimal Number 13 bytes
Floating Point Number 8 bytes
Currency 8 bytes
Option Set 4 bytes
Whole Number 4 bytes
Two Options (T/F) 1 byte


As you can see from the table above, the most taxing fields are indeed the Single Line Text and Multi Line Text.

There was an issue with field lengths over 4000 characters sync-ing to Outlook (due to SQL Express limitations, as described in the KB938065), but it’s supposed to be fixed now.