Primary Index vs. Secondary Index vs. Clustered Index
Is there any one who can tell me what is the exact difference between Primary index & Secondary index and clustered index?
Please share your answers and help me out.
Thanks in advance.
Indexing is a data structure technique to properly retrieve records from the database files based on some attributes on which the indexing has been done.
Indexing has following types:
Primary Index − Primary index is defined on an ordered data file. The data file is ordered on a key field. The key field is generally the primary key of the relation.
Secondary Index − Secondary index may be generated from a field which is a candidate key and has a unique value in every record, or a non-key with duplicate values.
Clustering Index − Clustering index is defined on an ordered data file. The data file is ordered on a non-key field.