The clustering index determines the physical order, while the non-clustering index is maintained separately and may contain multiple pointers to the same record.

The clustering index is always implemented as a dense index, whereas the non-clustering index is always implemented as a sparse index.

Both indexes determine the physical order of the records in the table.

The non-clustering index always results in faster query performance than the clustering index.

A non-clustering index is always implemented using a sparse indexing scheme.  

A non-clustering index directly determines the physical order of data records.  

A non-clustering index can only be built on numeric attributes.

A non-clustering index contains pointers to data records that may be stored in any order, separate from the index order.   

It eliminates the need for any secondary indexes on the table.  

It can significantly reduce I/O operations by keeping related data physically close together.   

It does not affect the physical storage order of records in any way. 

It always leads to faster point queries but can slow down range queries.  

When there are frequent updates to the indexed attribute that require every record to be re-indexed.  

When every record must be directly accessible through the index.  

When the file is sorted on the search key and only one index entry per block is sufficient for retrieval. 

When the file is unsorted and records are randomly stored.