Error
Error Code:
25P02
PostgreSQL Error 25P02: Transaction Already Failed
Description
Error 25P02 indicates that a previous SQL statement within the current transaction has failed, causing the transaction to enter an invalid state. Subsequent attempts to execute commands will also fail until the transaction is explicitly rolled back or committed.
Error Message
in failed sql transaction
Known Causes
3 known causesPrior Statement Failure
An earlier SQL statement (e.g., INSERT, UPDATE, DELETE, DDL) within the same transaction encountered an error, such as a constraint violation, syntax error, or deadlock.
Transaction Rollback State
The transaction has been internally marked for rollback-only due to a previous error, and subsequent statements are attempted before an explicit ROLLBACK command is issued.
Attempting Operations on Failed Transaction
After an error occurs, the application continues to send SQL commands to the database within the context of the already failed transaction, leading to this invalid state.
Solutions
4 solutions available1. Rollback the Failed Transaction easy
Explicitly roll back the current transaction to clear the failed state.
1
Connect to your PostgreSQL database using a client tool (e.g., `psql`, pgAdmin).
2
Execute the `ROLLBACK` command. This will discard any pending changes within the failed transaction.
ROLLBACK;3
You should now be able to issue new SQL commands.
2. Restart the Application or Connection easy
Restarting the application or client that initiated the transaction will often reset the connection and clear the failed state.
1
Identify the application or client process that is currently connected to PostgreSQL and experiencing the error.
2
Gracefully shut down the application or client. If a graceful shutdown is not possible, terminate the process.
3
Restart the application or client. A new connection will be established, and the failed transaction state will be gone.
3. Identify and Fix the Root Cause of Transaction Failure medium
Investigate why the transaction failed in the first place to prevent recurrence.
1
Review PostgreSQL logs for more detailed error messages preceding the 'Transaction Already Failed' error. Look for errors like constraint violations, deadlocks, or connection issues.
2
Examine the SQL statements within the application's transaction logic. Look for potential race conditions, incorrect data manipulation, or improper handling of concurrent operations.
3
If the cause is a deadlock, review your application's transaction isolation levels and locking strategies. Consider using `pg_locks` to diagnose deadlocks.
4
If the cause is a constraint violation, ensure your application logic validates data before attempting to insert or update.
5
Once the root cause is identified, implement the necessary fixes in your application code or database schema.
4. Restart PostgreSQL Server (Last Resort) advanced
As a last resort, restarting the PostgreSQL server will clear all active transactions and reset the server state.
1
Ensure you have proper backup and recovery procedures in place before attempting a server restart.
2
Connect to the server hosting your PostgreSQL instance.
3
Use the appropriate command to stop the PostgreSQL service. The command will vary based on your operating system and installation method.
# For systemd-based systems (e.g., Ubuntu 15.04+, CentOS 7+):
sudo systemctl stop postgresql
# For SysVinit-based systems (e.g., older Ubuntu/Debian, CentOS 6):
sudo service postgresql stop
# On Windows (using Services manager):
# Open services.msc, find the PostgreSQL service, and click Stop.4
Once the service has stopped, start it again.
# For systemd-based systems:
sudo systemctl start postgresql
# For SysVinit-based systems:
sudo service postgresql start
# On Windows:
# In services.msc, find the PostgreSQL service, and click Start.5
Verify that PostgreSQL is running and accessible.