title: Compare records in SQL database with an Excel, and update database accordingly
body: <p>I have a table with about 100 columns and about 10000 rows.
  Periodically, I will receive an Excel with similar data and I now need to update the table.
  If new rows exist in Excel, I have to add them to the db.
  If old rows have been updated, I need to update the rows in the db.
  If some rows have been deleted, I need to delete the row from my main table and add to another table.</p>
  
  <p>I have thought about proceeding as follows:</p>
  
  <p>Fetch all rows from db into a DataSet.
  Import all rows from Excel into a DataSet.
  Compare these 2 DataSets now using joins and perform the required operations.</p>
  
  <p>I have never worked with data of this magnitude and am worried about the performance. Let me know the ideal way to go about realizing this requirement.</p>
  
  <p>Thanks in advance. :)</p>