Which of the following is true about file formats? Open file formats may be either free or proprietary.

Open file formats are always free.

Free file formats may be either open or closed.

Proprietary files are always closed.

Name the range function that would generate the following list of integers values: 0,1,2,3,4,5.

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)?

With editing, word automatically displays a paste options button near the pasted or moved text. a. cut-and-paste b. drag-and-drop c. inline d. copy-and-carry