DATABASE FUNDAMENTALS
DATABASE CONCEPTS AND STRUCTURES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Foreign
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Primary
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Secondary
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Composite
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Detailed explanation-1: -A secondary index is a data structure that contains a subset of attributes from a table, along with an alternate key to support Query operations. You can retrieve data from the index using a Query, in much the same way as you use Query with a table.
Detailed explanation-2: -Structure of Index The search key is the database’s first column, and it contains a duplicate or copy of the table’s candidate key or primary key. The primary key values are saved in sorted order so that the related data can be quickly accessible.
Detailed explanation-3: -Definition. A primary index is an index on a set of fields that includes the unique primary key and is guaranteed not to contain duplicates. In contrast, a secondary index is an index that is not a primary index and may have duplicates.