An indexed file is a digital file stored on a computer that uses unique identifiers to categorize information. This indexing process is a simple file management technique that organizes data into special file folders, similar to a file label in a file cabinet. Programs and databases use these unique index labels to retrieve and store information.
Many types of indexing techniques are used in computer software engineering. Each type is designed for a specific purpose. Some examples include b-trees, hash tables, and alternate indexes. Building file system indexing programs requires a deep understanding of computer science and data access methods. The indexed file is a simple file made up of unique keys and data elements that are accessed by special database computer programs.
Internet search engines use special indexing techniques that store meta data about web sites and content. When a person executes a search, the criteria entered on the screen is compared against these defined indexes. The returned information is then ranked and displayed on the computer screen for review. An indexed file is updated on periodic bases by search engine, which ensures the content remains current.
A B-tree index is another type of indexed file that is common in mainframe programming languages. The B-tree index is an algorithm that puts a snapshot of the data into a hierarchical grouping of data. When a program is searching for data, it must first read the index to determine where the data is located. This type of searching technique is considered an extremely efficient method for data access.
Indexes typically contain both primary and secondary identifiers. These are unique keys that are designed to increase the efficiency of searching algorithms. The primary key is typically a numerical value that represents a unique identifier for the data. The secondary key is a more general data field, which works with the primary key to quickly locate information.
The iTunes music library also uses indexing to store and retrieve music files. This unique index is recalculated each time a new library is created. The index helps the iTunes program locate a song when a user searches for his music. Some unique keys for this type of index include artist name, song name, and album name.
Social networking programs also use an indexed file to store and retrieve information. These indexes are used to store photos, music, and video files for each user within the social network. The index file also provides a method to search for people by secondary attributes including school names, employment, and hobbies.