title: Calculating total data size of BLOB column in a table
body: <p>I have a table with large amounts of BLOB data in a column. I am writing a utility to dump the data to file system. But before dumping, I need to check if necessary space is available on the disk to export all the blob fields throughout the table.</p>
  
  <p>Please suggest an efficient approach to get size of all the blob fields in the table.</p>