The INDEX table having only two columns, one is a rowid and another is indexed-column (ordered).

The INDEX first sorts the data and then it assigns an identification for each row. In that case, if indexes are created on that column, which are accessed frequently, the information can be retrieved quickly. It takes a long time to find an information for one or combination of columns from a table when there are thousands of records in the table. INDEX can work properly and quickly for the columns that have many different values. The performance of an INDEX can not be recognized much when dealing with relatively small tables. INDEXES can locate information within a database very fast.Īn INDEX makes a catalog of rows of a database table as row can be pointed within a fraction of the time with a minimum effort.Ī table INDEX is a database structure which arranges the values of one or more columns in a specific order.

Note: The CREATE INDEX command is not a part of the ANSI SQL standard, and thus its syntax varies among vendors. One table may contain one or more INDEX tables. An INDEX is created on columns of a table. An INDEX can also be called a table and it has a data structure. The indexes can do an operation like SELECT, DELETE and UPDATE statement faster to manipulate a large amount of data.

The indexes are special objects which built on top of tables.

Sql server indexing