SAP ABAP Technical Questions (Data Dictonary)

1. What is data Dictionary?
2. What is the difference between open sql & native sql ?
3. Difference between Pooled, cluster & transparent tables?
4. What is Primary key, foreign key ? what is primary index? secondary index?
5.how many indexes can be created for a table?
6. what is a value table?
7. what are the components of a table?
8. what is a domain?
9. what is a data element?
10. what is data class?
11. can you create a table with out a data element?
12. can you create a field with out a data element?
13. What approach you prefer for creating a table?
14. Give few names of cluster tables in sap?
15. Give few names of pooled tables in sap?
16. give few names of transparent tables?
17. what is a buffer and how many types?
18. what is table maintenance generator and how to create that?
19. What is the transaction code? How to add new fields to a standard sap table ?
20. How many types of table joins are there? difference between inner join & outer join?
21. Difference between "select * from mara" and "select single * from mara"?
22. what is a match code ? Lock objects ? what are views?
23. what are logical tables/database?
24. what is the difference bet'n table and a structure?