The query optimizer constructs an initial query tree using join, selection, and projection operations. (a) True (b) False

Suppose relations R(A,B) and S(B,C,D) have the tuples shown below: R A B 5 3 4 46 8 479 Compute the result of the join query: SELECT A, R.B, S.B, C, D FROM R, S WHERE R.A

Write relational algebra expressions for database provided

20. Filtering and Slicing Pivot Tables a. Filter customer names to only show customers that begin with the letter B by left clicking the filter icon to show the filter drop down menu (the little triangle in the column header in the same cell as the text Customer Name), selecting Labels Filters, and Begins With. b. Filter product names to only show products that begin with letters between O-Z using Labels Filters →→ Between... c. Insert a Slicer using OrderDate and select Feb, May, and Aug. 21. Obtaining Details from Pivot Tables a. For Customer Name and Product Name: Bon app' and Pavlova, double left click the Number of Order Lines for 2018 (double left click on the 2). Note that the details of the two order lines will display in a new worksheet. b. Change the new worksheet name to Bon App Pavlova 2018 Details.

Optimize the following SQL Query by using Query Tree and Heuristic Rules: SELECT C.Fname, E.Fname FROM Employee AS E, Customer AS C, Order AS O WHERE E.EMP_ID=O.E_ID AND C.City=’Jeddah’ AND C.Customer_ID=O.C_ID AND E.EMP_ID=’12943’   You should show the Initial Query Tree and add a screenshot of the Query Tree after applying each rule.

12. R S AB [ 3 4 6 BCD 2 4 6 4 G 8 4 7 9 Compute the result of the following query: SELECT R.A, R.B, S.B, S.C, S.D FROM R OUTER JOIN S ON (R.A>S.B AND R.B=S.C) Which of the following tuples of R or S is dangling (and therefore need to be padded in the outer join)? a) (4,6,8) of S. b) (2,4,6) of S. c) (4,7,9) of S. d) (5,6) of R.

Composite datatypes can only have multi row &multi column values in them Answers: Yes No

What is the purpose of a hash function in hash table data structures?