Define Clustered and Non-Clustered Index. Clustered index exists as sorted row on disk.
Clustered index re-orders the table record.
Clustered index contains record in the leaf level of the B-tree.
There can be only one Clustered index possible in a table.
Non-clustered is the index in which logical order doesn’t match with physical order of stored data on disk.
Non-clustered index contains index key to the table records in the leaf level.
There can be one or more Non-clustered indexes in a table.
Explain the difference between clustered and non-clustered index.A clustered index reorders the way records are stored. A non clustered index is in which the logical order of the index does not match the physical stored order of the rows on disk. A clustered index is must faster because the index entries are actually data records. There can be just one clustered index per table while there can be up to 249 non clustered indexes