SQL Interview Questions #11: Define RDB Index

SQL code copied to buffer

Task 11:

Select the correct relational database index definition from the options below:

An database index is an arranged data structure that allows the database to locate relevant data on storage based on the values of the indexed columns without scanning the entire table. In most cases, an index speeds up data retrieval but slows down data modification by adding the cost of updating the index itself.

An index is a built-in search function within the database software.

An index is a mandatory component for every table in a database.

An database index is a duplicate copy of a table stored in a separate location for backup purposes.

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