title: Validate if a column has a null value
body: <p>Which SQL would be faster to validate if a particular column has a null value or not, why?</p>
  
  <p>1) SELECT * FROM TABLE1 WHERE COL1 IS NULL</p>
  
  <p>Execute this query and then check if you are able to read any records. If yes there are null values.</p>
  
  <p>2) SELECT COUNT(COL1) FROM TABLE1 WHERE COL1 IS NULL</p>
  
  <p>Read the count which is returned to determine if there are any null records</p>
  
  <p>Working with Oracle10g and SQLServer2005.</p>