Logging for updated smart large objects

When you update a smart large object, the database server does not log the entire object. Assume that the user is writing X bytes of data at offset Y with logging enabled for smart large objects. The database server logs the following information:

• If Y is set to the end of the large object, the database server logs X bytes (the updated byte range).
• If Y is at the beginning or in the middle of the large object, the database server logs the smallest of these choices:
  • Difference between the old and new image
  • Before-image and after-image
  • Nothing is logged if the before- and after-images are the same