Indexed Sequential Access

⬛A Allows records to be accessed either sequentially in the order they were
entered or randomly using an index

⬛Each index defines a different ordering of the records

⬛A database may have several indexes, based on the information required

⬛A key is specified in each index

⬛It is a method of indexing data for fast retrieval

⬛Data is organised into records which consist of fixed length fields

⬛A set of hash tables known as indexes contain "pointers" into the records

⬛Individual records can be retrieved without having to search the entire file

⬛Indexes can be searched quickly, thereby allowing the database to access only
the records it needs

⬛Searches use an index which will narrow down the records/data to be searched

⬛Then that section of the file is searched sequentially to find the record required.

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