Author Question: What is a checkpoint? What will be an ideal response?[br][br][b][color=#165FFA]Question ... (Read 80 times)

kamilo84 · **on:** Jul 7, 2018

What is a checkpoint?

What will be an ideal response?

Question 2

Describe the update set-to-null option (for implementing a referential integrity constraint).

What will be an ideal response?

alexanderhamilton · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

A checkpoint is a part of a recovery log. When a checkpoint is created, all updates recorded in the recovery logand as a result any updates to data stored in memoryare written to the database in the data file on the disk.

Answer to Question 2

The update set-to-null option allows a record to be changed if its primary key value is referred to by a foreign key value of a record in another relation. As a consequence, in all of the records where the foreign key value refers to the primary key being changed, the value of the foreign key is set to null.