title: SQL Table Size And Query Performance
body: <p>We have a number of items coming in from a web service; each item containing an unknown number of properties. We are storing them in a database with the following Schema.</p>
  
  <p>Items<br>
    - ItemID<br>
    - ItemName</p>
  
  <p>Properties<br>
    - PropertyID<br>
    - PropertyName<br>
    - PropertyValue<br>
    - PropertyValueType<br>
    - TransmitTime<br>
    - ItemID [fk]</p>
  
  <p>The properties table is growing quite large since it stores the properties for each item, each time the web service is called. My question is this: at what point should we stop adding new records to the Properties table, and archive older Property records according to their transmit time? When does the properties table become too large, and take too long to query? Is there a rule of thumb?</p>
  
  <p>Thanks.</p>