Chapter 19, Problem 3PE

Explanation of Solution

Deleting a log record with normal logging:

• With normal logging, all log records except the ones mentioned below can be deleted.
  • All logs that are related to transactions, which were active during the most recent checkpoint.
  • All logs that are related to transactions, which were started after the checkpoint.
• All the above-mentioned log records are needed for recovery purposes.
• More number of records can be deleted after each checkpoint, when multiple number of checkpoints are used.
• Thus, the system looks out for a point in the log records where all earlier log records before that point can be deleted and goes ahead with the deletion...