File Organization 2

Question 1

What are the Types of File Organization

Answer 1

• Heap Files(Unordered Records)- Depends on insertion order.
  Easy to insert but hard to retrieve
• Sorted Files(Ordered Records)-
  Sorted using an identifier or key value.
  Insertion is expensive but retrieval is easy
• Hashing Techniques- Organizational structure using hashing. Database uses buckets not blocks. Record must be hashed then appended to the right bucket

Question 2

Describe Unordered Files(Heap Files) Mentioning how records are searched and inserted

Answer 2

Also called a heap or a pile file.
* New records are inserted at the end of the file. Record insertion is quite efficient
* To search for a record, a linear search through the file records is
necessary. This requires reading and searching half the file blocks on the average, and is hence quite expensive.
* Reading the records in order of a particular field requires sorting the
file records.

Question 3

Describe Ordered Files(Sequential Files) Mentioning how records are searched and inserted

Answer 3

• File records are kept sorted by the values of an ordering field.
• Insertion is expensive: records must be inserted in the correct order.
• A binary search can be used to search for a record on its ordering field value.
  This requires reading and searching log2 of the file blocks on the average, an improvement over linear search.
• Reading the records in order of the ordering field is quite efficient.