title: What is the maximum size of a primary key in Firebird?
body: <p>I need to set a Varchar(255) field as the primary key of a database table in Firebird 2.1. </p>
  
  <p>I get error messages saying that the field size is too large. I'm using UTF8 as my character set and the default page size of 4096. </p>
  
  <p>Is it possible to do this in Firebird? I need to ensure that this column is unique.</p>