How to diagnose and fix the 25P03 idle_in_transaction_session_timeout error code in Postgres.

The 25P03 error code in PostgreSQL corresponds to idle_in_transaction_session_timeout, which signifies that a session has been terminated because it was idle in a transaction for longer than the idle_in_transaction_session_timeout setting. This setting is a part of PostgreSQL’s configuration that helps to avoid issues with long-running transactions holding locks for more time than necessary, which can lead to contention and performance problems.

When a session exceeds the specified timeout while idle in a transaction, PostgreSQL will terminate the session to release the held resources. Here are some scenarios where this might happen, along with explanations and solutions:

Example 1: Long-Running Transaction Exceeding the Timeout

If you start a transaction and then don’t perform any operations for a period longer than the idle_in_transaction_session_timeout, the session will be terminated.

-- Start a transaction
-- Execute some SQL command
UPDATE accounts SET balance = balance - 100.00 WHERE account_id = 1;

-- If you now wait without issuing a COMMIT/ROLLBACK longer than the timeout,
-- the session will be terminated with the 25P03 error.


Check for long-running transactions in your application logs or by querying the pg_stat_activity system view.


Ensure that transactions are completed (either committed or rolled back) promptly:

-- Start a transaction
-- Execute some SQL command
UPDATE accounts SET balance = balance - 100.00 WHERE account_id = 1;
-- Complete the transaction

Example 2: Forgotten Transaction in Application Code

Sometimes, an application might start a transaction and then due to a bug or logic error, fail to commit or roll back, leaving the transaction open and idle.


Review application code to find where transactions are started and ensure they are always properly closed. Also, look for error handling that might inadvertently leave a transaction open.


Implement proper error handling and ensure that all transactions are closed. For example, in pseudocode:

try {
} catch (Exception e) {

Example 3: Unintentionally Long Idle Times in Interactive Sessions

During an interactive database session, such as with psql or another database tool, you might start a transaction and then get distracted, leaving the transaction idle.


Monitor your interactive sessions to ensure you don’t leave transactions open without activity.


Make it a habit to either commit or roll back transactions as soon as your work is complete. If you know you will be away, you can set a reminder or use tool-specific features to alert you to open transactions.

Example 4: Misconfigured idle_in_transaction_session_timeout

The idle_in_transaction_session_timeout setting might be configured too low for your application’s workflow, leading to premature session terminations.


Check the current setting of idle_in_transaction_session_timeout in the PostgreSQL configuration file or by running:

SHOW idle_in_transaction_session_timeout;


Adjust the idle_in_transaction_session_timeout setting in the postgresql.conf file to a value that better suits your application’s needs, and then reload the PostgreSQL configuration:

-- To change the setting for the current session
SET idle_in_transaction_session_timeout = '15min';
-- Or change in the postgresql.conf file for a permanent adjustment

Remember to reload the configuration after making changes:

SELECT pg_reload_conf();

In summary, to diagnose and fix the 25P03 error, you should:

  1. Ensure that your application logic properly closes transactions.
  2. Adjust the idle_in_transaction_session_timeout setting if necessary.
  3. Monitor both application and interactive sessions to avoid leaving transactions open without activity.
  4. Consider implementing application-side or database-side monitoring to alert on long-running transactions.

Leave a Comment