title: Is there a faster alternative to Substring function?
body: <p>I have an SSRS report that passes a string of counties to a stored procedure.  Because of the way I had to build the report I needed to append a GUID of 36 characters to the counties.  I then strip the GUID in the stored procedure using a substring function:</p>
  
  <pre><code>and county IN(Select substring(item, 1, LEN(item)-36) from fnsplit(@County, ',')
  </code></pre>
  
  <p>The report runs in about 8 seconds, which is a vast improvement over the REPLACE function.  But I'd still like to get this to run faster.  Does anyone know of a better way to do this?  I'm not allowed to included indexes on tables, so that won't be an option.</p>