What is meant by an index?

COBOL SQL Interview Questions

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What is meant by an index?

An index ia set of row identifier (RIDs) or pointers that are logically ordered by the values of a column that has been specified as being an index. Indexes provide faster access to data and can enforce uniqueness on the row in a table.

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Other Interview Questions

• What is a view? Why use it ?
• What do you accomplish by GROUP BY ... HAVING clause ?
• In the WHERE clause what is BETWEEN and IN?
• When can an insert of a new primary key value threaten referntial integrity?
• What are foreign keys?
• What techniques are used to retrieve data from more than one table in a single SQL statement?
• What is a cursor? Why should it be used ?
• Can you use MAX on a CHAR column?
• My SQL statement SELECT AVG(SALARY) FROM EMP-TABLE yields inaccurate results. why?
• What is a synonym? How is it used
• More...