I am confused about indexing being densed or sparse, Read a lot of answer but can’t figure out
- Primary Index is always sparse : since indexing is done of key attribute and records(files) are ordered so we create index only for anchor of the block(group of records).
- Secondary index is dense : Since indexing is done on the basis of Non-key/key attribute and records are un-ordered.
- Clustering indexing can be sparse or dense: Sparse when we create index for Distinct non-key attributes attributes and there are multiple records having same non-key attributes and Dense when there is unique record with non-key attribute.
- B- tree indexing is Dense ; since we have and indexing for every key attribute.
- B+ tree is Sparse since indexing is not for every record and is only for some records.
Please correct me If I am wrong at some point and If I am right then please comment.