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Clustered Index
Non 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.
Clustered Index is a special type of index that reorders the way records in the table are physically stored.Therefore can only have one clustered index.
Non-clustered index in which the logical order of the index does not match the physical stored order of the row in the disk.
A clustered index determines the physical order of data in a table for this Reason a table can have only one clustered index.Primary key constraint creates clustered indexes automatically if no clustered index exists on the table.
A non-clustered index is analogues to an index in a text book. The data is stored in one place, the index in another place. The index will have pointers to the storage location data. A table can have more than one non-clustered index.
CLUSTER INDEX HAVE NO SEPRATE PLACE REQUIRE TO SAVE A TABLE
BUT NON CLUSTER INDEX HAVE REQURIE SEPERATE PLACE TO SAVE A TABLE
one table can only have one clustered index.
one table can have many non-clusterd index.
A clustered index requires no seperate storage than the table storage, anon-clusterd index requires seperate storage than the table storage to store the index information.
A clustered index actually describes the order in which records are physically stored on the disk, hence the reason you can only have one. A Non-Clustered Index defines a logical order that does not match the physical order on disk. A clustered index is essentially a sorted copy of the data in the indexed columns.
Clustered Index
Non Clustered Index
A clustered index actually describes the order in which records are physically stored on the disk, hence the reason you can only have one. A Non-Clustered Index defines a logical order that does not match the physical order on disk
Index is special look-up table that database uses to speed up data retrieval. We have2 types of index > Clustered and non-clustered index.
clustered index -
1). Can have only one clustered index on a table.
2). Doesn't allow null values.
3). Exists on physical level.
4). Assigned for primary keys.
5). Requires no separate storage than table storage.
Non-clustered index -
1). We can have many clustered index (~).
2). allows null value.
3). Exists on logical level.
4). Assigned for unique keys.
5). Requires separate storage than table storage to store the index information.
clustered index - Primary key to database. It can only be used 1 per table
non-clustered index - similarly to a foreign key. you can use it in multiple times in a multiple table
A clustered index actually describes the order in which records are physically stored on the disk
A Non-Clustered Index defines a logical order that does not match the physical order on disk.