Suppose that a School offers several courses; each course has several sections. A specific COURSE must exist before creating a specific SECTION of the course. In this case, what cardinality will appear for the relationship between COURSE and SECTION in the ERD?

Duplicating objects creates copies that a. move differently than the original object b. erase the original object c. look and act like the original object d. add events to a game

You have a linux system that has a 1000gb hard disk drive, which has a 90gb partition containing an ext4 filesystem mounted to the / directory and a 4gb swap partition. currently, this linux system is only used by a few users for storing small files; however, the department manager wants to upgrade this system and use it to run a database application that will be used by 100 users. the database application and the associated data will take up over 200gb of hard disk space. in addition, these 100 users will store their personal files on the hard disk of the system. each user must have a maximum of 5gb of storage space. the department manager has made it very clear that this system must not exhibit any downtime as a result of hard disk errors. how much hard disk space will you require, and what partitions would you need to ensure that the system will perform as needed? where would these partitions be mounted? what quotas would you implement? what commands would you need to run and what entries to /etc/fstab would you need to create? justify your answers.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?