Flashcards
404 Concepts
Flashcards do conjunto (5)
- 1What is the buffer manager?Software layer responsible for bringing pages from disk to main memory as needed.
Manages available main memory by partitioning it into a collection of pages called the buffer pool. - 2What is the process for when a page is requested from the buffer manager?1. Checks BP to see if some frame contains it. If so, pin it. Else bring it in and
a. Choose frame to evict
b. If the evicted page is dirty, write it to disk
c. Bring in the new page
2. Returns the main memory address of the frame containing the requested page to the requestor - 3Describe pinningPin + when requested (inform of dirty if applicable)
When it is 0, it can be evicted. - 4How does DBMS implement LRU?Queue of 0 pin pages. Head is least recently used.
- 5How does the DBMS implement clock?When pin = 0, reference = 1 current++
When pin = 0 && reference = 1, ref 0, curr+
When pin = 0 && ref = 0, evict
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- CS404 FlashCards sobre 404 Concepts, criado por Curtis Hermanson em 05-01-2017.
- Criado por
- Curtis Hermanson
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