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Informix interview questions and Answers

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Last update: 30 Nov 2019, 12 Questions
Informix interview questions

Most Frequently Asked Informix interview questions

1. Who developed Informix?

The Informix database was designed by Roger Sippl in the late 1970s and was initially developed in his company Informix Corporation and later in April 2001; IBM acquired it.

2. What is a chunk in Informix?

A chunk is a physical portion of the disk on which the Informix stores its data. A fragment can be a raw partition or a file system file.

3. Explain the Informix Instance.

An Informix instance is a database server which manages the one or more than one Informix databases.

4. What is a Database Object in IBM Informix?

The Database object is a table or a view or any other type of objects supported by Informix. The Database objects are created using a statement SQL CREATE for these types of objects, and the database objects have owners.

[database[@server_name]:][owner.]object

5. What is the role of Binary Large Object in Informix?

A large binary object which is also known as a Blob is a collection of the binary data which is stored as a single entity in a database management system. Blobs are the audio or the images or the other multimedia objects.

6. What is the use of Key-Value Locking In Informix?

Informix database uses a concept which is called key-value locking. Key Value locking is used to lock the deleted row. When the server deletes a row, then the critical values in the indexes of the table are not removed immediately. Instead, each key value is marked as deleted, and a lock is placed on the critical value.

7. What is the use of Extent in Informix? If a table is designed without declaring the extent sizes, then the Informix uses by default 16 pages for the first and eight pages for each subsequent extent. Extent sizing should be done when the table is created.
8. Explain about Informix 4GL.

Informix 4GL is a fourth-generation database which was developed in the mid-'80s. Informix 4GL provides the flexibility to work without the use of third generation programming languages like COBOL. Informix 4GL is mostly used in developing business applications.

9. List down the features of Informix 4GL.
  • Informix 4GL database can handle the NULL values as the inputs and outputs within an Informix 4GL function.
  • Informix 4GL database does not require the input or output parameters when publishing or subscribing to a web service.
  • Informix 4GL database clients can also process structured data such as ARRAYs and RECORDs from the other 4GL applications.
  • Informix 4GL database now includes the direct support for file I/O
10. What is a light scan in Informix?

A light scan is the sequential data scan of the data tables when the number of pages in the table is more than the number of buffers in the buffer pool.

11. Name the SQL Joins that are Available In Informix.

There are four joins in the Informix:-

  • INNER JOIN
  • LEFT / RIGHT OUTER JOIN
  • FULL OUTER JOIN
  • CROSS JOIN
12. What Are The Informix Isolation Levels?
  • DIRTY READ: Dirty Read Reads the data without checking whether the data is committed or not. During the read, no locks are held.
  • COMMITTED READ: Committed Read reads only the determined data. During the read, no locks are held.
  • REPEATABLE READ: Reads only the committed data. In this read, a shared lock is held on the rows. Other sessions can get the shared locks on those rows, but no one can get an exclusive lock.
  • CURSOR STABILITY