Indexs are used for the faster retrivel of data.
Two types of indexes
1)Cluster index,2)Non-clustered index
clustered index is physically stored a table can have 1 clustered index
non clustered index is logically stored a table can have 249 non clustred index
Clustered index will be created by default when u create primary key on a column. So we can create one clustered index per table. clustered index is stored in serial passion.
NON CLUSTERED INDEX:
Non clustered index will be created automatically when u create unique key on a column. A table can have no.of unique keys, so we can create no.of non clustered indexes per table.
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