HackerRank Bit Mapping and Hashing Quiz-1

A bitmap is the data structure that immediately pops in your head when there's a need to map boolean information for a huge domain into a compact representation.

 It is a very popular data structure whenever memory space is at a premium.

Redis, being an in-memory data structure server, provides support for bit manipulation operations.

bitmap is a mapping from some domain (for example, a range of integers) to bits. It is also called a bit array or bitmap index.

A bitmap is a type of memory organization or image file format used to store digital images.

A device-independent bitmap (DIB) is a format used to define device-independent bitmaps in various color resolutions. The main purpose of DIBs is to allow bitmaps to be moved from one device to another (hence, the device-independent part of the name). A DIB is normally transported in metafiles , BMP files.

Free-Space Bitmaps are one method used to track allocated sectors by some file systems. 

Free-Space Bitmaps are one method used to track allocated sectors by some file systems. 

• Wasteful on larger disks: The simplistic design starts wasting large amounts of space (in an absolute sense) for extremely large volumes


• Poor scalability: While the size remains negligible as a percentage of the disk size, finding free space becomes slower as the disk fills. If the bitmap is larger than available memory, performance drops precipitously on all operations


• Fragmentation: If free sectors are taken as they are found, drives with frequent file creation and deletion will rapidly become fragmented. If the search attempts to find contiguous blocks, finding free space becomes much slower for even moderately full disks.

One of the strongest reasons for using bitmap indexes is that the intermediate results produced from them are also bitmaps and can be efficiently reused in further operations to answer more complex queries.