[Solved] What is an expression index in PostgreSQL? — Ans: An index built on the result of a function or expression applied to table... | PostgreSQL

PostgreSQL - Indexing Strategies

What is an expression index in PostgreSQL?

AAn index that stores only the primary key values

BAn index that automatically updates without any user input

CAn index built on the result of a function or expression applied to table columns

DAn index that is created only on text columns

Step-by-Step Solution

Solution:

Step 1: Understand what an expression index is
An expression index stores the result of a function or expression applied to one or more columns, not just the raw column values.
Step 2: Compare options with this definition
Only An index built on the result of a function or expression applied to table columns describes an index built on expressions or functions applied to columns.
Final Answer:
An index built on the result of a function or expression applied to table columns -> Option C
Quick Check:
Expression index = Function-based index [OK]

Quick Trick: Expression indexes store computed values, not raw columns [OK]

Common Mistakes:

Master "Indexing Strategies" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

What is an expression index in PostgreSQL?