Posted by Raj
Clustered indexes Vs Non-clustered indexes-MySql
- Clustered index will physically order the data based on the values in the index.
- A non clustered index is a special type of index that stores the records in logical order rather than physical order. This means, a table can have many non clustered indexes. More non clustered indexes per table means more time it takes to write new records.
- A clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages.
- A non clustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk. The leaf node of a non clustered index does not consist of the data pages. Instead, the leaf nodes contain index rows.
- Clustered index is physically stored a table can have 1 clustered index.
- Non clustered index is logically stored a table can have 249 non clustered index.