What is a checkpoint? What will be an ideal ...

[kamilo84]

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]

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.

[kamilo84]

Excellent

[nanny]

Gracias!