File Organization in Database [SQL Server]

File Organization In Database[COMPLETE CONCEPT]

FILE ORGANIZATION:

           Storage and access method of a file is called file organization.

TYPES OF FILE ORGANIZATION:

1.Sequential File Organization

2.Direct access File Organization

SEQUENTIAL FILE ORGANIZATION:

When we have to access data in sequence.

Example:

Tape-drive. In tape drive if we want to access the 2nd video we have to go through the 1st then we can access the second one . We can’t jump directly to  2nd .

ADVANTAGE OF SEQUENTIAL FILE ORGANIZATION:

Sequential saves memory. Because there is no meta data (header/footer) with a single record.

USES OF SEQUENTIAL FILE ORGANIZATION:

Sequential file organization is helpful when we have to access the whole batch . i.e Electricity bills.

DRAWBACKS OF SEQUENTIAL FILE ORGANIZATION:

1.Time loss

2.Searching is difficult in Sequential file Organization

3.If we try to insert a new data we have to reorganize the whole data.

4.If we are searching a data which is not present in the records. It will search the whole data then tell that the data is not present.

DIRECT FILE ORGANIZATION:

Example:

Hard Drive.

ADVANTAGES OF DIRECT FILE ORGANIZATION:

1.Time saving

2.Searching is easy in Direct file Organization

TYPES OF DIRECT FILE ORGANIZATION:

1.Indexed Sequential

2.Hashing

INDEXED SEQUENTIAL:

           

Indexed Sequential is same as Table of Content in books.

HASHING:

   Hashing is a function but not a specific function. We can made our hashing function.

TYPES OF HASHING FUNCTION:

1.Division method

2.Folding method

DIVISION FUNCTION:

x mod y return remainder. If remainder of two numbers are same then it is called hashing conflict.

SOLUTION OF HASHING CONFLICT:

Add 1 to the remainder.

FOLDING METHOD:

You can fold a number to find that in which track the given record should go.

FOR EXAMPLE:

Suppose a record with Student ID 8530 & you have to use folding method to tell that  which hard drive’s track will hold this record ?

  8      5        3       0

            8       5

      +    3      0

      --------------

           11     5   <------- This record will save in 5th 
     ---------------
track in hard drive!

THANK YOU... 🙂