the other handfile reorganization may involve changing the entire organization of the file we will discuss file organization in detail in the next section file organization we know that file is collection of related records the main issue in file management is the way in which the records are organized inside the file because it has significant effect on the system performance organization of records means the logical arrangement of records in the file and not the physical layout of the file as stored on storage media since choosing an appropriate file organization is design decisionit must be done keeping the priority of achieving good performance with respect to the most likely usage of the file thereforethe following considerations should be kept in mind before selecting an appropriate file organization methodrapid access to one or more records ease of inserting/updating/deleting one or more records without disrupting the speed of accessing record(sefficient storage of records using redundancy to ensure data integrity although one may find that these requirements are in contradiction with each otherit is the designer' job to find good compromise among them to get an adequate solution for the problem at hand for examplethe ease of addition of records can be compromised to get fast access to data in this sectionwe will discuss some of the techniques that are commonly used for file organization sequential organization sequentially organized file stores the records in the order in which they were entered that isthe first record that was entered is written as the first record in the filethe second record entered is written as the second record in the fileand so on as resultnew records are added only at the end of the file sequential files can be read only sequentiallystarting with the first record in the file sequential file organization is the most basic way to organize large collection of records in file figure shows records numbered from to - stored in sequential file once we store the records in filewe cannot make any changes to the records we cannot even delete the records from sequential file in case we need to delete or beginning record update one or more recordswe have to replace the records by creating of file new file record in sequential file organizationall the records have the same size and the same field formatand every field has fixed size the records are sorted based on the value of one field or combination of two or more record fields this field is known as the key each key uniquely identifies record + record in file thusevery record has different value for the key field records can be sorted in either ascending or descending order sequential files are generally used to generate reports or to perform sequential reading of large amount of data which some programs need record - to do such as payroll processing of all the employees of an organization record - end of file sequential files can be easily stored on both disks and tapes table summarizes the featuresadvantagesand disadvantages of sequential figure sequential file file organization organization