Introduction to DB2 Interview Questions and Answers
DB2 is basically one database designed by IBM. It is mainly managing relational database management system (RDBMS) which helps to store data in proper relational approach which help for analyzing and retrieving data very efficiently. DB2 admin expert’s people are really very much highly demanded in the current market scenario, the base salary for the same also very attractive.
Now, if you are looking for a job which is related to DB2 then you need to prepare for the 2019 DB2 Interview Questions. It is true that every interview is different as per the different job profiles. Here, we have prepared the important DB2 Interview Questions and Answers which will help you get success in your interview.
In this 2019 DB2 Interview Questions article, we shall present 10 most important and frequently asked DB2 Interview questions. These questions are divided into two parts are as follows:
Part 1 – DB2 Interview Questions (Basic)
This first part covers basic DB2 Interview Questions and Answers
Q1. Provide given some clear definition or explanation regarding picture clause in DB2. And in the case of null indicator variable how it can be utilized properly?
Picture clause is one the key feature which needs to be defined for identifying specific characteristics and as well as requirements of editing of a, particularly elementary items. This picture clause can be different for varieties activity in DB2 or mainframe DB2, we can able to use S9(4) COMP as picture clause for null indicator variable.
Q2. Every RDBMS database has one common disadvantage of creating the deadlock. Now DB2 also followed the same RDBMS structure, so deadlocks also been generated in DB2. Please explain how or which specific components need to be check for identifying DB2 deadlocks?
DB2 deadlocks is one of the critical problems for any kind of DB2 user, currently DB2 is running for two kinds of approaches one is for IBM mainframe where DB2 is the only option to use, but facility is deadlocked condition or any other critical problem of RDBMS database normally not introducing for using the same in Mainframe object. But this kind of problematic scenario can easily be generated when DB2 has been using for any kind of web application or some else rather than Mainframe. Deadlocks conditions normally generated in case of some concurrency issues which are critical for web application users. Normally IRLM (Internal Resource Lock manager) which is known as locking service component of DB2 has been provided all the locking-related services who manages every concurrent issue in DB2 database.
Let us move to the next DB2 Interview Questions
Q3. Every RDBMS database always followed some well define the structure for the executed SQL statement in their environment. In case of DB2 which component is responsible for executing the SQL statement? Explain with an example?
SQL statements can be varieties for every kind of databases. IBM Db2 has also followed some specific SQL structure define in their environment. Those SQL can be executed smoothly compare to other database and performance of the same little better than other always. Normally some of the define database service components are handling the same very smartly and execute it as faster as possible compared to other databases. IBM Db2 is mainly concentrating on executing SQL query very smartly without huge performance issue. DB2 has provided queue result of executing a query by this IBM DB2 database service components, and managing the huge buffering pool without loss of any critical transactional data store in the database.
Q4. In DB2, is it possible to use one of the popular aggregator keywords like MAX if the column defines as CHAR? If yes, please explain the same how we can do it.
This is the basic DB2 Interview Questions asked in an interview. Yes, it is possible to use MAX easily in case of the column defined as CHAR. But it is required to ensure that a CHAR column should always contain some numeric value, in that case, MAX will always provide the correct result in case of DB2. If there have some non-numeric value then there have a lot of possibility of receiving some wrong kind of data. As an example suppose you are willing to get some MAX value of ‘www’, ‘099’, ‘99’ kind of data. Then it may give some kind of the wrong result as DB2 supported AS/400 which follows EBCDIC to store values. That’s why 099 will store as 99 in the database. So keep 99 always be a maximum value kind of approach.
Q5. One of the common approaches in the RDBMS database, suppose we are expecting the average salary for an entire organization from a specific table by using common aggregator AVG. Is there any possibility of given some wrong average value for any kind of common mistake? If yes explain about the mistake and how we can recover the same?
We are normally calculating an average value by using AVG aggregator for one of the columns which holding numeric values. Sometimes developer by mistake mentions that column as expected null, then the average value will always come as wrong as it will consider the null value as one of the values of salary. Also, they did some mistake of mentioning 0 in the salary field, rather than mentioning 0 deactivate or removing the member who doesn’t have any salary will give more appropriate result.
Part 2 – DB2 Interview Questions (Advanced)
Let us now have a look at the advanced DB2 Interview Questions.
Q6. Suppose we are willing to shutdown DB2 database or startup one DB2 database. Then which component needs to be used for handling startup and shutdown?
DB2 start up and shut down can be handled by system define service components of DB2. There have two key system service components, global db2start and db2stop are mainly managing for starting and shut down of DB2 database.
Q7. Suppose we are willing to apply some locks in the DB2 database, then which level of execution we can able to add those locks. Give some more details on the same?
DB2 database locking or any RDBMS database locking system are well defined. There have several phases they can apply locking:
- Page: locking can be done for an entire page. In that case none of the table accessible at the lock period.
- Table: locking the table. One that specific table will not be accessible by another request.
- Table Space: tablespace can be the lock, in that case, all the table using that specific tablespace cannot accessible during the locking period by another request.
Let us move to the next DB2 Interview Questions
Q8. Suppose we are planning to add some isolation level on DB2 database. Is it possible? If yes, then explain which level we can able to do this?
In DB2 we can specify the isolation level for bind step. Bind step in DB2 is actually the compilation process define on this database platform. BIND basically ensure proper compilation of Cobol programming. It basically helps to DB2 optimizer for preparing SQL statement in the executable code.
Q9. Suppose we have executed one DML statement like UPDATE, INSERT, and DELETE kind of command on one specific table. Now those statements normally return some number of rows which are impacted or updated, on which field helps to show the number of rows in SQLCA?
This is the most asked DB2 Interview Question in an interview. For checking the same we need to validate SQLERRD which actually holding how many rows are impacted or updated.
Q10. What will be the defined length of physical storage for storing the timestamp in IBM Db2 database?
Timestamps normally have taken 10 bytes. YYYY-MM-DD HH:MM: SS: NNNNNN
This has been a guide to the list of DB2 Interview Questions and Answers so that the candidate can crackdown these DB2 Interview Questions easily. Here in this post, we have studied top DB2 Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –