SAP DB Interview Questions

1. What are the steps in moving data or databases between servers?

2. what is spool buffer?

3. What are the tools used in SAP Implementation? How do you create Alert Messages?
One of the Tools being used for SAP Implemention is QuickSizer, which is used to size the SAP Server based on number of users using various modules in SAP.

Alert Message is created in the CCMS monitor using TCodes RZ20 and RZ21. The values for Alert AutoReaction Methods are defined using the TCode RZ21, while this particular method is assigned to the Monitoring Tree Element (MTE) in the TCode RZ20.

One as well can have an Alert Management System, where alerts from the Entire Landscape can be configured in a Central Moitoring System from where it can trigger a alert mail or SMS to the concerned Administrator

4. When spool buffer is full and new spool request is raised what happens to the request?where does the request stored?
The new spool request will be in the queue. If it is urgent request then the current request will be be stoped and newrequest will be send.

5. Whats the difference between R3trans and Tp in SAP-DBA?
R/3trans is the R/3 system transport program which can be used for transporting data between different SAP systems ,even when they dont belong to the same group. R3trans normally is not used directorly but called from the Tp controle program or by the R/3 upgrade. Tp is the basic tool for the transporting the request.

6. What is “Group by” in Select statement?
Answer1:
Group by is used to fetch a unique data from a column.

Answer2:
A "group by" is used to group selected rows in a table to perform arg functions on them. Rows not included in the "group by" clouse and not part of ARG functions cannot be used ...(logical grouping of data) or orerations performed (on groups of data) can be used with the "HAVING" clause to further refine the output.
ex of some ARG functions : SUM() , MIN(),MAX(), AVG()

7. Select statement to read data into internal tables. Types of Select statements
select * from database table into (internal table name)
the above statement collects data into the header area of the internal table.
and
select * from database table into table (internal table name)
the above statement collects the data into the body area directly .

8. Explain “Commit” and “Roll back”
The Oracle RDBMS provides a transaction model based on a unit of work. The PL/SQL language supports most, but not all, of the database model for transactions (you cannot, for example, ROLLBACK FORCE). Transactions begin with the first change to data and end with either a COMMIT or ROLLBACK.

COMMIT makes the database changes permanent and visible to other database sessions.

ROLLBACK undoes the changes made in the current transaction either to the beginning of the transaction or to a savepoint. A savepoint is a named processing point in a transaction, created with the SAVEPOINT statement. Rolling back to a savepoint is a partial rollback of a transaction, wiping out all changes (and savepoints) that occurred later than the named savepoint.

9. What happens “Update” command is used without where clause ?
Answer1:
It will update all the records with same name in the particular field of the table.

Answer2:
If we dont mention "WHERE" clause in the UPDATE statement, it will update all records satisfying the given condition (if given any ) in the table !

Answer3:
Based on query condition. it will update all the fields which are mentioned in the query.
ex: update employee set firstname= @firstname,lastname=@lastname where employee_id =@employee_id.
so in the above case nothing wil be happen if you used where clause or not.
if you have many statements in the query you need to use the where clause.

10. What are logical databases?
Answer1:
insert' will add a new record or a new row into the database table.
'Update' will modify a record in the DB table.
'Modify' it is a combination of both insert and update...

Answer2:
INSERT - Add a new record into the database table.

MODIFY - If record is available it modifies otherwise it wont modify.

UPDATE - If record is available its update the record otherwise it creates a new record.


11. Difference between “Insert”, “Update” and “Modify”
INSERT - Add a new record into the database table.

MODIFY - If record is available it modifies otherwise it wont modify.

UPDATE - If record is available its update the record otherwise it creates a new record.

12. “Catch” Command
Trying to catch any runtime errors programatically or manually we use this statement catch.