title: How to do maintenance on data for a long running web application
body: <p>Looking for suggestions....</p>
  <p>We have an ASP.NET web application running under windows environment with data storage on SQL Server. Application has been in production environment for over 3 years. Mostly client needs access to last 6 months of data only so remaining data mostly not needed and he feels when we do so application would be more faster than previous as data querying would be reduced. So we are looking for a best industry practice that we can manage old data.</p>
  <p>Old data should be maintained as history of data and should not be deleted permanently. Maybe when needed we should be able to look.</p>
  <p>We hope/believe that industry definitely will came across such a situation and there is some definitely best standards to follow meeting our requirements.</p>
  <p>Thanks,</p>
  <p>Selva</p>