Thursday, January 14, 2010

File-based Systems& Limitations of File-Based Approach

File-based Systems• Collection of application programs that perform services for the end users (e.g. reports).
• Each program defines and manages its own data
• E.g. is a C++ system that accepts and stores data. In such case the sequence in which the fields are recorded is coded in the program, not in the file.

Limitations of File-Based Approach

• Separation and isolation of data
– Each program maintains its own set of data.
– Users of one program may be unaware of potentially useful data held by other
programs.
– Duplication of data
– Same data is held by different programs.
– Wasted space and potentially different values and/or different formats for the same item.

• Duplication of data
– Same data is held by different programs.
– Wasted space and potentially different values and/or different formats for the same item.

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