21.What is the size of Informix page?

The most common page size used is 2KB, though some systems uses 4KB page.

22.Why a foreground write in Informix decrease performance?State the reason for the same?

foreground writes (FG) should always be zero. A foreground write is caused when a session needs to have a page from disk placed into the buffer pool, but there are no clean/free buffers available. In ...

23.What is the company from which the Informix products are released?

Sorrry. IBM has been releasing Iformix products ever since it took over Informix corp.

24.Mention the database server operating modes available for Informix?

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...

25.What is the option or command used in Informix for finding which dbspace a database resides?

from command line# onmonitor ->Logical-Logs->Databases ----- or ------ Following shell script, you can easily find out database name and in which dbspace #!/usr/bin/ksh OUTPUT=lstdbs.out...

26.Explain about light scans in Informix?

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 i...

In some circumstances, the database server can bypass the overhead of the buffer pool when it performs a sequential scan. Such a sequential scan is termed a light scan.Light scans can be used only for...

27.What is chunk in Informix?

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 ac...

28.What is extent in Informix?

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.

29.What is Informix instance?

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 us...

30.What is Informix Binary Large Object?

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. ...

31.Who conceived and designed the Informix database management system?

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

32.What are the uses of key value locking in Informix?

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. Instea...

33.Explain the concept of fragment elimination in Informix?

In certain circumstances, Informix can eliminate fragments from a search. When this occurs, system resources such as CPU cycles, cache buffers, and LRU queues are freed for other operations. Whether f...

34.What is mirroring in Informix?

Mirroring is the process of replicating a dbspace for the purpose of reducing the risk of data loss in the event of a hardware failure. When mirroring is in place, both the primary and the mirror chun...

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