[Solved] What is the main purpose of using INCLUDE in a PostgreSQL index? — Ans: To add extra columns to the index for faster SELECT queries without searching... | PostgreSQL

PostgreSQL - Indexing Strategies

What is the main purpose of using INCLUDE in a PostgreSQL index?

ATo change the data type of indexed columns

BTo create a unique constraint on the indexed columns

CTo delete columns from the index

DTo add extra columns to the index for faster SELECT queries without searching on them

Step-by-Step Solution

Solution:

Step 1: Understand the role of INCLUDE in indexes
INCLUDE adds extra columns to the index that are not used for searching but can be returned in queries.
Step 2: Identify the benefit of these extra columns
These extra columns help avoid reading the main table, speeding up SELECT queries that need those columns.
Final Answer:
To add extra columns to the index for faster SELECT queries without searching on them -> Option D
Quick Check:
INCLUDE adds columns for SELECT speed [OK]

Quick Trick: INCLUDE adds columns to speed SELECT, not for searching [OK]

Common Mistakes:

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What is the main purpose of using INCLUDE in a PostgreSQL index?