Solution:Step 1: Analyze the ORDER BY clauseThe query orders by total_time DESC, so it sorts queries by total execution time from highest to lowest.Step 2: Understand the LIMIT clauseLIMIT 3 restricts output to top 3 rows after sorting.Final Answer:The 3 queries with the highest total execution time

[Solved] Given the query:SELECT query, calls, total_time FROM pg_stat_statements ORDER BY total_time DESC LIMIT 3;What does this query return? | PostgreSQL

PostgreSQL - Performance Tuning

Given the query:

SELECT query, calls, total_time FROM pg_stat_statements ORDER BY total_time DESC LIMIT 3;

What does this query return?

AThe 3 most recent queries executed

BThe 3 queries with the fewest calls

CThe 3 queries with the lowest average execution time

DThe 3 queries with the highest total execution time

Step-by-Step Solution

Solution:

Step 1: Analyze the ORDER BY clause
The query orders by total_time DESC, so it sorts queries by total execution time from highest to lowest.
Step 2: Understand the LIMIT clause
LIMIT 3 restricts output to top 3 rows after sorting.
Final Answer:
The 3 queries with the highest total execution time -> Option D
Quick Check:
ORDER BY total_time DESC LIMIT 3 = top 3 slowest total time queries [OK]

Quick Trick: ORDER BY total_time DESC shows slowest total time queries [OK]

Common Mistakes:

Confusing total_time with calls
Assuming it shows recent queries
Thinking it orders by average time

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Given the query:

Step 1: Analyze the ORDER BY clause

Step 2: Understand the LIMIT clause

Final Answer:

Quick Check:

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