[Solved] You tried to create an expression index with:CREATE INDEX idx_expr ON sales (price * discount);But PostgreSQL returned a syntax error. What is the problem? | PostgreSQL

PostgreSQL - Indexing Strategies

You tried to create an expression index with:
CREATE INDEX idx_expr ON sales (price * discount);
But PostgreSQL returned a syntax error. What is the problem?

AExpression indexes require double parentheses around the expression

BYou cannot create indexes on expressions involving multiplication

CThe table name is missing

DThe index name is invalid

Step-by-Step Solution

Solution:

Step 1: Check expression index syntax
Expression indexes must have the expression enclosed in double parentheses to be valid.
Step 2: Identify the syntax error cause
The given statement uses single parentheses, causing a syntax error.
Final Answer:
Expression indexes require double parentheses around the expression -> Option A
Quick Check:
Double parentheses fix syntax error [OK]

Quick Trick: Use double parentheses for expressions to avoid syntax errors [OK]

Common Mistakes:

Using single parentheses for expressions
Thinking multiplication is not allowed
Ignoring syntax error details

Master "Indexing Strategies" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Time

You tried to create an expression index with:

Step 1: Check expression index syntax

Step 2: Identify the syntax error cause

Final Answer:

Quick Check:

Want More Practice?