the index file is more sicurity checked and contains more information about the acess . for example An indexed file is a computer file with an index that allows easy random access to any record given its file key.
The key must be such that it uniquely identifies a record. If more than one index is present the other ones are called alternate indexes.
The COBOL language supports indexed files with the following command in the FILE CONTROL section. however a sequential file isA file that contains records or other elements that are stored in a chronological order based on account number or some other identifying data. In order to locate the desired data, sequential files must be read starting at the beginning of the file. A sequential file may be stored on a sequential access device such as magnetic tape or on a direct access device such as magnetic disk. Contrast with random-file.
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Content of sequential file can't be accessed directly while index file content can be accessed directly through pointer. Sequential file is time consuming in comparison with index file.
Example: Index of book - index file
Example: Bundle of plates - sequential file
An indexed sequential file is a type of file organization where data records are stored sequentially in the order of key values. An index is maintained to help locate records quickly. This combination of sequential storage and indexing allows for efficient access to data in both sequential and random access patterns.
Advantages of indexed-sequential file organization include efficient access to records through an index and sequential storage for faster retrieval. However, disadvantages may include increased complexity in managing the index and potential performance degradation due to index maintenance overhead.
Indexed-sequential file organization allows for efficient storage and retrieval of records by combining the benefits of sequential access (fast for batch processing) and direct access (quick for individual record retrieval). It provides faster access to records compared to purely sequential files while maintaining sequential organization for improved batch processing performance. The index allows for quick access to specific records without needing to search through the entire file.
Serial file organization stores records in a linear format, while sequential file organization stores records in a specific order defined by a key field. In serial file organization, records don't have to be retrieved in a specific order, whereas in sequential file organization, records are retrieved based on the key field's order.
One disadvantage of sequential file organization is that it can be slow for locating and accessing specific records, as the entire file must be scanned sequentially from the beginning to find the desired data. Additionally, inserting or deleting records in a sequential file can be inefficient and may require reorganizing the entire file.
index file is organized with the help of any key as index number at rondomly but index sequencial file organized with the help of any index sequentialy rajesh patel
file organization is of 3 types sequential,direct and indexed sequential where how data is accessed in eash file is decided where as file maintainence is
Index sequential files store records in sequential order and use an index to quickly locate specific records. Relative files store records based on their physical position in the file, allowing for direct access to records using their relative position within the file.
Explain the difference between sequential and direct file access.A. Sequential access to data is used when the data has to be read from the start, in sequence. It is the normal method of access for magnetic tape. Direct access is used when it is possible to jump directly to a file or data item without reading through all the items stored before it. This is the normal method used for hard disks.
sequential file organization index file orgaization diect file orgaization
Indexed sequential file organization. =In indexed sequential file organization, the records arestored in sequence according to a primary key and an index is created to allow random access of the file. This type of organization also allows the file to be accessed sequentially. Indexed sequential is the most commonlyused type of file organization. writer-k.k.b -montanna
An indexed sequential file is a type of file organization where data records are stored sequentially in the order of key values. An index is maintained to help locate records quickly. This combination of sequential storage and indexing allows for efficient access to data in both sequential and random access patterns.
the difference is that sequential organization: this are records are stored and accessed in a particular order sorted using a key field serial organisation: records in a file are stored one after another. You need to go first file in order to reach the required file.
Advantages of indexed-sequential file organization include efficient access to records through an index and sequential storage for faster retrieval. However, disadvantages may include increased complexity in managing the index and potential performance degradation due to index maintenance overhead.
These lecture notes describe those file organizations in detail and compares and contrasts them: http://www.cim.mcgill.ca/~franco/OpSys-304-427/lecture-notes/node53.html
Indexed-sequential file organization allows for efficient storage and retrieval of records by combining the benefits of sequential access (fast for batch processing) and direct access (quick for individual record retrieval). It provides faster access to records compared to purely sequential files while maintaining sequential organization for improved batch processing performance. The index allows for quick access to specific records without needing to search through the entire file.
Serial file organization stores records in a linear format, while sequential file organization stores records in a specific order defined by a key field. In serial file organization, records don't have to be retrieved in a specific order, whereas in sequential file organization, records are retrieved based on the key field's order.