Explain why the LSN need not be included in pages stored in the database when physical logging is used together with a cache and log buffer.
What will be an ideal response?
With physical logging the LSN is used to enforce the write-ahead policy and is not used during recovery. Its value lies in determining the relationship between updates to a page after it has been brought into the cache and the corresponding update records in the log. Update records corresponding to updates to the page during its previous stay in the cache must have been moved to mass storage before the page was swapped out. Hence, it is sufficient to associate the LSN with each page in the cache, but it need not be stored in the page. When a page is brought into the cache it is clean and the associated LSN can be initialized to a null value.
You might also like to view...
Laptop computers present an ergonomic problem because the screen and keyboard are attached to each other.
Answer the following statement true (T) or false (F)
The ________ used in Word's mail merge feature is a file that contains organized information for the letters or labels being created
A) joined letter B) merge template C) document feed D) data source
Which of the following statements is not true?
A. All IRB sessions share a common memory space. B. Classes, methods and variables that are defined in one IRB are not accessible in another session. C. New IRB sessions can be started by opening a new console window and typing IRB. D. New IRB sessions cane be started from within an existing irb accessing by typing IRB.
Which project settings can you change later?
What will be an ideal response?