What causes ORA-00054?

Pipeline runs a TRUNCATE while an active DML session holds a row lock. Concurrent pipelines target the same table simultaneously. A previous pipeline session was left open and holds a lock. DDL migration script runs during business hours when writers are active

How do I fix ORA-00054?

Step 1: Find the blocking session: `SELECT sid, serial#, username, status FROM v$session WHERE blocking_session IS NOT NULL;`.. Step 2: Kill the blocking session if safe: `ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;`.. Step 3: Schedule DDL operations (TRUNCATE, DROP, ALTER) in a maintenance window with no active writers.. Step 4: Replace TRUNCATE+INSERT with a DELETE+INSERT inside a transaction to avoid DDL locking.. Step 5: Add retry logic with a short delay to pipeline code that hits this error.

High severitylocking

Oracle Database Error:
ORA-00054

What does this error mean?

A DDL statement (ALTER TABLE, TRUNCATE, DROP) or a NOWAIT lock request could not acquire the required lock because another session holds it.

Common causes

1Pipeline runs a TRUNCATE while an active DML session holds a row lock
2Concurrent pipelines target the same table simultaneously
3A previous pipeline session was left open and holds a lock
4DDL migration script runs during business hours when writers are active

How to fix it

1Step 1: Find the blocking session: `SELECT sid, serial#, username, status FROM v$session WHERE blocking_session IS NOT NULL;`.
2Step 2: Kill the blocking session if safe: `ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;`.
3Step 3: Schedule DDL operations (TRUNCATE, DROP, ALTER) in a maintenance window with no active writers.
4Step 4: Replace TRUNCATE+INSERT with a DELETE+INSERT inside a transaction to avoid DDL locking.
5Step 5: Add retry logic with a short delay to pipeline code that hits this error.

Example log output

ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

Frequently asked questions

Can I avoid ORA-00054 without killing sessions?

Yes — use WAIT N instead of NOWAIT in your lock request, or restructure the pipeline to avoid DDL operations on live tables (use staging tables and atomic renames instead).

Source · docs.oracle.com/error-help/db/ora-00054