SAP DB Frequently Asked Questions

1). What are the tools used in SAP Implementation? How do you create Alert Messages?  

Ans: One of the Tools being used for SAP Implementation is Quick Size, 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 Tcode RZ20 and RZ21. The values for Alert Auto Reaction 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 Monitoring System from where it can trigger a alert mail or SMS to the concerned Administrator

2). When spool buffer is full and new spool request is raised what happens to  

        the request? Where does the request stored? 

Ans: The new spool request will be in the queue. If it is urgent request then the current request will be stopped and new request will be send. 

3). What is the difference between R3trans and Tp in SAP-DBA? 

Ans: R/3trans is the R/3 system transport program which can be used for transporting data between different SAP systems, even when they don’t belong to the same group. R3trans normally is not used directory but called from the Tp control program or by the R/3 upgrade. Tp is the basic tool for the transporting the request. 

4). What is “Group by” in Select statement? 

Ans1:   Group by is used to fetch a unique data from a column. 

Ans2:
 

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" clause and not part of ARG functions cannot be used ... (logical grouping of data) or operations 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 ()

5). Select statement to read data into internal tables. Types of Select statements 

Ans: 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.

6). Explain “Commit” and “Roll back”

Ans:   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 save point. A save point is a named processing point in a transaction, created with the SAVEPOINT statement. Rolling back to a save point is a partial rollback of a transaction, wiping out all changes (and save points) that occurred later than the named save point.

7). What happens “Update” command is used without where clause?

Ans1: It will update all the records with same name in the particular field of the table. 

Ans2:

If we don’t mention "WHERE" clause in the UPDATE statement, it will update all records satisfying the given condition (if given any ) in the table ! 

Ans3:

Based on query condition. it will update all the fields which are mentioned in the query.
Ex: update employee set first name= @first name, last name=@last name where employee_id =@employee_id.
 

So in the above case nothing will be happen if you used where clause or not.
If you have many statements in the query you need to use the where clause.

8). What are logical databases? 

Ans1:

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...

Ans2:
 

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.

9). Difference between “Insert”, “Update” and “Modify”

Ans:            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. 

10). “Catch” Command 

Ans: Trying to catch any runtime errors programmatically or manually we use this statement catch.