WRITE SHORT NOTES ON INDEX STRUCTURE OF FILES?

There are two basic parts of indices

1.   Ordered indices

2.   Hash indices

Every technique must be evaluated on the basis of these factors:

• Access types
• Access time
• Insertion time
• Deletion time
• Space overhead

Ø  Ordered indices

Ø  Primary index

Ø  Dense and sparse indices

Ø  Multilevel index

Ø  Index update

Ø  Secondary indices

B+-Tree index files

B+-Tree index structure is the most widely used of various index structures that maintain their efficiency despite insertion and deletion of data.

Ø  Structure of B+-Tree

Ø  Queries on B+-Tree

Ø  Update on B+-Tree

Ø  B+-Tree file organization

Ø  B-Tree index files