Debugging xv6 using gdb Lab instructions. Continue from our previous lab, compile xv6. run make qemu-gdb. Then, in another window, run gdb from the xv6 directory, and then run che command source .gdbinit Now. in the gdb window run the following (shown in bold font) gdb) b exec gdb) c gdb) c Cgdb) c Answer the following question. 1. What does command "b" do? 2. What does command "c" do? 3. What do you see by executing the commends (b, c, c, c)? Why do you see that? REFERENCES It is possible to use GDB with xv6. To do this instead of running make qemu or make qemu- nox,run make qemu-gdb or make qemu-nox-gdb respectively. Then, in another window, run gdb from the xv6 directory, and then run the command source .gdbinit within GDB. Then, within GDB, you can set breakpoints

Question 35 If there are several operators with same priority in an arithmetic expression of an SQL statement then the priority will be For division for multiplication From left to right For addition

Is the following table in First Normal Form? If so, how would you get it into first normal form.         SalesPerson/Product table         Order Number Product  Number Salesperson ID SalesPerson Name Commission Percentage Year of Hire Department Number Department                 Name Product Name Unit Price Quantity 137 19440 15 Baker 10 1995 73 Commercial Sales Hammer 17.50 473   24013             Saw 26.25 170   26722             Pliers 11.50 688 186 16386 7 Adams 15 2001 59 Home Sales Wrench 12.95 1745   19440             Hammer 17.50 2529

For questions 6-9, create a truth table for each statement. 6. A ⋀ ~B 7. ~(~A ⋁ B) 8. (A ⋀ B) → C 9. (A ⋁ B) → ~C

question B is x = y^z not x = y^2