Informix Interview Questions and Answers, Informix Interview Questions and Answers Freshers, Informix Interview Questions and Answers, Informix Interview Questions
Before getting on to the Informix interview questions, the student must know that the Informix is a continuously varying field which needs the students as well as professionals to upgrade their skills with the new features and knowledge, to get fit for the jobs associated with Informix. This post related to Informix Interview Questions and Answers, Informix Interview Questions and Answers Freshers, Informix Interview Questions and Answers, Informix Interview Questions will help you let out find all the solutions that are frequently asked in you upcoming Informix interview.
Over thousands of vacancies available for the Informix developers, experts must be acquaintance with all the component of Informix technologies. This is necessary for the students in order to have in-depth knowledge of the subject so that they can have best employment opportunities in the future. Knowing every little detail about Informix is the best approach to solve the problems linked with problem.
APTRON has spent hours and hours in researching about the Informix Interview Questions and Answers, Informix Interview Questions and Answers Freshers, Informix Interview Questions and Answers, Informix Interview Questions that you might encounter in your upcoming interview. All these questions will alone help you to crack the interview and make you the best among all your competitors.
First of all, let us tell you about how the Informix technology is evolving in today’s world and how demanding it is in the upcoming years. In fact, according to one study, most of the companies and businesses have moved to the Informix. Now, you cannot predict how huge the future is going to be for the people experienced in the related technologies.
Hence, if you are looking for boosting up your profile and securing your future, Informix will help you in reaching the zenith of your career. Apart from this, you would also have a lot of opportunities as a fresher.
These questions alone are omnipotent. Read and re-read the questions and their solutions to get accustomed to what you will be asked in the interview. These Informix interview questions and answers will also help you on your way to mastering the skills and will take you to the giant world where worldwide and local businesses, huge or medium, are picking up the best and quality Informix professionals.
This ultimate list of best Informix interview questions will ride you through the quick knowledge of the subject and topics like Database Server, Monitoring Database Server,Managing Shared Memory. This Informix interview questions and answers can be your next gateway to your next job as a Informix expert.
These are very Basic Informix Interview Questions and Answers for freshers and experienced both.
Q1: What is chunk in Informix?
A1: A chunk is a physical portion of disk on which Informix stores its data. A chunk can be either a raw partition or a file system file. Informix suggests that a chunk’s name be a symbolic link to the actual chunk. For example, if you are using /dev/rdsk/c6t0d0s1 as a chunk, you could create a symbolic link named /dev/informix/chunk1 that points to /dev/rdsk/c6t0d0s1. That way, if there are ever any problems with that disk, you could replace the disk with another one and just change the symbolic link.
Q2: What is the option or command used in Informix for finding which dbspace a database resides?
A2: from command line# onmonitor ->Logical-Logs->Databases.
Q3: Mention the database server operating modes available for Informix?
A3: Informix IDS provide following modes:-
1)Online mode -> This is the normal operating mode of the database server.
2)Offline mode? -> The database server is not running. Shared memory is not allocated.
3)Quiescent mode -> This is the normal operating mode of the database server.
Administrators use this mode to perform maintenance functions that do not require the execution of SQL and DDL statements.
Only the administrator (user informix) can access the database
server.
4)Single-User mode -> This mode is an intermediary mode between Quiescent mode and Online mode.
?Administrators use this mode to perform any maintenance task, including tasks requiring the execution of SQL and DDL statements. Administrators can also perform all other functions available in Online mode. You can see the current database server mode by executing the onstat – utility from the command.
Q4: Who developed informix?
A4: IBM releasing.
Q5: What are the uses of key value locking in Informix?
A5: – The database server uses a concept called key-value locking to lock the deleted row. When the database server deletes a row, key values in the indexes for the table are not removed immediately. Instead, each key value is marked as deleted, and a lock is placed on the key value. One of the most important uses for key-value locking is to assure that a unique key remains unique through the end of the transaction that deleted it.
– Without this protection mechanism, user A might delete a unique key within a transaction, and user B might insert a row with the same key before the transaction commits. This scenario makes rollback by user A impossible. Key-value locking prevents user B from inserting the row until the end of user A’s transaction.
Q6: What is Informix Binary Large Object?
A6: A binary large object, also known as a blob, is a collection of binary data stored as a single entity in a database management system. Informix invented an alternative backronym, Binary Large Object. Blobs are typically images, audio or other multimedia objects, though sometimes binary executable code is stored as a blob.
Q7: Who conceived and designed the Informix database management system?
A7: The Informix database management system was conceived and designed by Roger Sippl in the late 1970s. Informix was founded in 1980, went public in 1986, and for a period during the 1990s Informix was the second most popular database system, after Oracle.
Q8: What is Informix instance?
A8: An Informix instance is a single connection to shared memory. It is represented by one or more on init processes. When Informix is started or stopped, these processes appear and disappear. Informix used to use the term “server” when referring to an instance, hence the environment variable DBSERVERNAME.
Q9: Explain about light scans in Informix?
A9: Light scans occur under the following conditions: The optimizer chooses a sequential scan of the table. The number of pages in the table is greater than the number of buffers in the buffer pool. The isolation level obtains no lock or a shared lock on the table: Dirty Read (including non logging databases) isolation level Repeatable Read isolation level if the table has a shared or exclusive lock
Committed Read isolation if the table has a shared lock.
Q10: What is extent in Informix?
A10: If a table is designed without specifying extent sizes, Informix uses a default of 16 pages for the first and 8 pages for each subsequent extent. Extent sizing is done when the table is initially created.
Q11: What Is Informix Binary Large Object?
A11: A binary large object, also known as a blob, is a collection of binary data stored as a single entity in a database management system. Informix invented an alternative backronym, Binary Large Object. Blobs are typically images, audio or other multimedia objects, though sometimes binary executable code is stored as a blob.
Q12: Explain About Light Scans In Informix?
A12: Light scans occur under the following conditions: The optimizer chooses a sequential scan of the table. The number of pages in the table is greater than the number of buffers in the buffer pool. The isolation level obtains no lock or a shared lock on the table: Dirty Read (including non logging databases) isolation level Repeatable Read isolation level if the table has a shared or exclusive lock Committed Read isolation if the table has a shared lock
Q13: Can I Ask About Perl, Dbi And Dbd Informix? Other Products?
A13: You may ask questions about Perl, DBI and DBD::Informix, but only if an IBM or Informix database is involved, somehow — it is not a general forum for arbitrary questions about Perl. However, there are alternative forums that you should also use, described in the product.
Q14: Can I Install Informix On A Non-english Version Of Windows Nt?
A14: Yes, but you need to install version 7.30 TC 6 or higher.
Q15: How Would You Convert A Secondary Server Into A Primary Server ?
A15:
- EXECUTE FUNCTION task(“ha sds primary”,”srv_slave”);
- If it is HDR and the secondary becomes the new standalone server: onmode -d standard
Q16: Explain Checkpoints And Why In 9.4 They Were Better Than In Previous Versions Of The Engine?
A16:
- You are still using 9.4 ? It’s out of support for 3 years … . We upgraded from 10.00FC6 to 11.50FC7 last year.
- The first Informix database I started to administrate was IDS 10.00FC4. So my best guess is that 9.4 introduced partially non blocking checkpoints (fuzzy checkpoints ?), these being superseded in the latter versions.
- The checkpoint is the moment when Informix will flush the contents from the bufferpool to disks.
Q17: How Could You Increase The Speed Of Ontape/onbar Backups ?
A17:
- On a platform with fast cpus, write low performance and compresable data, the ontape output may be piped and compressed before getting on disk (less IO write operations).
- With onbar, greater backup speeds can be achived by:
- Increase the number of onbar threads -> BAR_MAX_BACKUP
- Increase the buffers used by onbar (if memory is available) ? BAR_NB_XPORT_COUNT
- Use a fast storage for the storage pool (We use onbar + IBM Tivolli Storage Manager)
- Consider taking incremental backups
Q18: Can You Explain Pdq Priority?
A18: By setting PDQ PRIORITY the DBA can change the query execution priority and increase the number of internal threads spawned by Informix to satisfy the query. Also, some memory allocation strategies differ upon setting PDQPRIORITY.
Q19: Explain The Purpose Of Optimizer Directives And How/why You Would Use Them
A19: A DBA can use directives mostly to change / test / evaluate the execution plan (costs / benefits) for a query, by forcing an index / change join order / etc.
Q20: Why Is Update Statistics Important To A Database?
A20:
- Running update statistics will update the system catalog information about the database.
- This information is used by the Informix optimizer to calculate costs and execution plans for day to day queries. Lack of up-to-date information about data distributions may result in severely bad plans.
Informix Conclusion Interview FAQs
We know the list of Informix Interview Questions and Answers, Informix Interview Questions and Answers Freshers, Informix Interview Questions and Answers, Informix Interview Questions is overwhelming but the advantages of reading all the questions will maximize your potential and help you crack the interview. The surprising fact is that this Informix interview questions and answers post covers all the basic of the Informix technology and you have to check out the FAQs of different components of Informix too.
However, you will be asked with the questions in the interview related to the above mentioned questions. Preparing and understanding all the concept of Informix technology will help you strengthen the other little information around the topic.
After preparing these interview questions, we recommend you to go for a mock interview before facing the real one. You can take the help of your friend or a Informix expert to find the loop holes in your skills and knowledge. Moreover, this will also allow you in practicing and improving the communication skill which plays a vital role in getting placed and grabbing high salaries.
Remember, in the interview, the company or the business or you can say the examiner often checks your basic knowledge of the subject. If your basics is covered and strengthened, you can have the job of your dream. The industry experts understand that if the foundation of the student is already made up, it is easy for the company to educate the employ towards advance skills. If there are no basics, there is no meaning of having learnt the subject.
Therefore, it’s never too late to edge all the basics of any technology. If you think that you’ve not acquired the enough skills, you can join our upcoming batch of Informix Training in Noida. We are one of the best institute for Informix in noida which provide advance learning in the field of Informix Course. We’ve highly qualified professionals working with us and promise top quality education to the students.
We hope that you enjoyed reading Informix Interview Questions and Answers, Informix Interview Questions and Answers Freshers, Informix Interview Questions and Answers, Informix Interview Questions and all the FAQs associated with the interview. Do not forget to revise all the Informix interview questions and answers before going for the Informix interview. In addition to this, if you’ve any doubt or query associated with Informix, you can contact us anytime. We will be happy to help you out at our earliest convenience. At last, we wish you all the best for your upcoming interview on Informix Technology.
