Saved Bookmarks
| 1. |
If Possible, Determine The Buffer-management Strategy Used By The Operating System Running On Your Local Computer System, And What Mechanisms It Provides To Control Replacement Of Pages. Discuss How The Control On Replacement That It Provides Would Be Useful For The Implementation Of Database Systems? |
|
Answer» The typical OS uses LRU for buffer replacement. This is OFTEN a bad STRATEGY for databases. As explained in Section 11.5.2 of the text, MRU is the BEST strategy for nested loop join. In general no SINGLE strategy handles all scenarios well, and ideally the database system should be given its own buffer cache for which the replacement policy takes into account all the performance related issues. The typical OS uses LRU for buffer replacement. This is often a bad strategy for databases. As explained in Section 11.5.2 of the text, MRU is the best strategy for nested loop join. In general no single strategy handles all scenarios well, and ideally the database system should be given its own buffer cache for which the replacement policy takes into account all the performance related issues. |
|