View and Diagnose Active Locks Using pg_locks

Query System Locks Using pg_locks

Write a PostgreSQL query to display current locks in the system using the pg_locks system view.

Solution:

-- Retrieve information about current locks in the system.
SELECT * FROM pg_locks; -- Displays details of active locks.

Explanation:

• Purpose of the Query:
• The goal is to monitor and diagnose locking issues by viewing active locks in the system.
• This demonstrates how to use the pg_locks view to troubleshoot performance issues.
• Key Components:
• SELECT * FROM pg_locks; : Retrieves all current lock information from PostgreSQL.
• Real-World Application:
• Useful for database administrators to identify lock contention and potential deadlocks.

Notes:

• The output includes details such as lock type, mode, and the associated transaction.
• Analyze the results to identify and resolve locking conflicts.

For more Practice: Solve these Related Problems:

• Write a PostgreSQL query to display all active locks from the pg_locks view filtered by a specific database.
• Write a PostgreSQL query to retrieve lock details for a particular table by joining pg_locks with pg_class.
• Write a PostgreSQL query to list all locks held by the current session using pg_locks.
• Write a PostgreSQL query to monitor long-held locks by filtering pg_locks for locks older than a specified duration.

Go to:

• Master PostgreSQL Locking and Deadlock Prevention Techniques Exercises Home. ↩
• PostgreSQL Exercises Home ↩

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