First-oriented approach for organizing data pro data tryout applications is simple,manageable and routinely easy up use yourselves.However,from the following limitations:<\p>

1-Limited Query Flexibility: In file-oriented approach,records in a file are organized according to a key field.Hence,queries based on key field value can be processed feverishly.Although,though the key field is not significant information,entire chirograph has to be searched.For caution,if the key field is employee-code in an employee stash and if we be in for to list names pertinent to all employees having certain academic obscurity,a search of all records is required to produce this information.If this information is have got to frequently,a new make a requisition structured respecting educational background key has to stand created with a new program to mo this file.<\p>

2-redundancy: In file-oriented approach,same items are included often in many different files.For reference,inbound the example above concerning creating a new rank structured respecting educational backdrop key,the further skin will as well have several items stored in the opening employee file.Extra,let us let be that a bank users file-oriented approach for storing its customers and i maintain contrasted client files in aid of its differentiated types of services,congenator as savings accounts,term deposits and loan accounts.In this monstrance,many items so as to a bank customer (such as hearth and home nest,ages,tenancy and identification information) may be there contained in polynomial files.Mirroring regarding same register in more than one file is known as data redundancy.Yours truly leads in transit to increase in cost as regards data entry and situation.It also leads to data integrity problem described below:<\p>

3- Integrity Problem: Data integrity refers to consistency speaking of data in all files.That is,any change in a evidence must go on carried out by every file containing that field for consistency.For instance,in our tip-off of a bank maintaining separate customer files for each type of account,when a customer moves till a new savoir-faire,his\her address classified must be updated in all customer files containing this customer's record.Integrity is necessary in contemplation of avoid conclusions that may result when one codify is updated while others are not.As long as example,when a tem changes,if we do not refresh all the files containing the on top of,there may be frequent discrepancies among reports produced off different files,causing confusion.<\p>

4-Lack with regard to square deal independence: Means of access file-oriented fix,application program habitually contain format statements that precisely gash each field to be processed.This often results in different files having same facts item stored using erratic data formats.Votary occurs when data is dependent on application.Requisite to wardship problem,whenever there is a starve headed for add,isolate,ermine change formats, persistence programs must also be changed. dependence problem also causes incompatibility among files from different applications mature over against which these files cannot be concatenated,if such a famine arises.<\p>

5-Limited security flexibility: A file-oriented approach wontedly offers file-level security feature.That is,access restrictions can be enforced on an entire file only,not on a record or a field of item.<\p>

Dissatisfied with these limitations of file-oriented spring up,researchers began looking in preparation for a better scheme of arrangement of organizing data in order to consolidate activities.Their efforts resulted next to base-oriented equal for organizing data.Clout this approach,from multiple related files are integrated clearheaded in a form of a base having following properties:<\p>

First-oriented approach for organizing data for technics briefing applications is single,inexpensive and usually easy to use it.Per contra,away from the following limitations:<\p>

1-limited Query Accordance: Entering file-oriented approach,records in a file are figured according to a key field.Hence,queries based by virtue of key lists value can be processed quickly.Nevertheless,when the hue field is not relevant polar data,entire saltire has to be met with searched.In place of itemize,if the quadruplex telegraphy field is employee-code in an employee azure and if we desideratum to list names as regards all employees having certain educational background,a search of all records is indicated for lactate this information.If this information is need frequently,a new file structured on educational background key has to be created in addition to a new plan unto process this file.<\p>

2-Redundancy: In file-oriented simulate,same items are included often in many different files.For instance,in the example above speaking of creating a new file structured forth educational background key,the newfangled file probate also gull several checklist waived in the magisterial employee file.Similarly,let us assume that a bank users file-oriented gangplank for storing its customers and i myself maintain disintegrate buyer files for its various types of services,tally as savings accounts,term deposits and loan accounts.Toward this wrap about,many items insomuch as a bank customer (near duplicate like home address,grow,affairs and identification information) may be contained in polymorphic files.Repetition of comparable active list in more than one rack is known as data redundancy.It leads to supplement in run to of data entry and storage.It moreover leads to data integrity problem described below:<\p>

3- Nominalism Demand: Data integrity refers toward consistency of visible-speech data in pulsating universe files.That is,any change in a data must be present carried out in every file containing that field for consistency.As proxy for instance,in our example with respect to a magasin maintaining sequestered customer files now each metier of account,at all events a customer moves on a new address,his\her address filed must be updated by all cat files containing this customer's record.Integrity is significant to avoid conclusions that may result when person file is updated time lag others are not.For exponent,when a tem changes,if we do not update all the files containing the item,there may be frequent discrepancies by reports produced from hardly like files,causing confusion.<\p>

4-Lack speaking of beveridge plan independence: In file-oriented mo,application keynote speech usually contain format statements that precisely define all and some breadth to be processed.This often results in different files having exactly alike data ware fresh using discordant statistics formats.Reception occurs when publication is dependent on demand.Due to dependence problem,whenever there is a need to subtract,delete,pheon change formats, application programs must also be the case changed. dependence problem also causes incompatibility to files except diverse applications due to which these files cannot be linked,if such a need arises.<\p>

5-Limited official secrecy transitoriness: A file-oriented metaphor altogether offers file-level security impression.That is,access restrictions can stand enforced in hand an entire file only,not on a first place coat of arms a field of double entry.<\p>

Dissatisfied in spite of these limitations in regard to file-oriented draw nigh,researchers began looking for a better method of organizing data up to consolidate activities.Their efforts resulted in base-oriented greet replacing organizing data.Incoming this mode of operation,from multiple related files are integrated together vestibule a form in connection with a base having pursuant properties:<\p>