MCQs
Yes, Indexes are stored on diskIndexes take memory slots which are located on the disk.
Column storeA database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes.
DisablingA database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes.
A composite index is a combination of index on 2 or more columnsA composite index is an index on two or more columns of a table.
CoveringA covered query is a query where all the columns in the query's result set are pulled from non-clustered indexes.
All of the mentionedA database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes.
2They are clustered index and non clustered index.
It is used for pointing data rows containing key valuesNonclustered indexes have a structure separate from the data rows. A nonclustered index contains the nonclustered index key values and each key value entry has a pointer to the data row that contains the key value.
Clustered index is built by default on unique key columnsNonclustered indexes have a structure separate from the data rows. A nonclustered index contains the nonclustered index key values and each key value entry has a pointer to the data row that contains the key value.
It makes harder for sql server engines to work to work on index which have large keysIndexes tend to improve the performance.