MySQL error 1192 appears when a statement is issued while tables are locked or a transaction is still open, blocking the requested command.
MySQL Error 1192: ER_LOCK_OR_ACTIVE_TRANSACTION occurs when you attempt an operation while a table is locked or a transaction is still open. Commit or roll back the transaction, or unlock the tables, then rerun the statement to resolve the error.
ER_LOCK_OR_ACTIVE_TRANSACTION
The server blocks a statement when it detects that the session still holds explicit table locks or has not ended a START TRANSACTION block.
MySQL protects data consistency by refusing operations that would conflict with pending locks or uncommitted changes.
The error is triggered at runtime, not at parse time, so a query can run fine in development yet fail under production load when locks last longer.
The condition appears during DDL or metadata statements such as ALTER TABLE, CREATE INDEX, or LOCK TABLES when issued inside an open transaction.
It also fires if a session manually locked tables with LOCK TABLES and forgot to run UNLOCK TABLES before executing an incompatible command.
High-concurrency workloads, long-running reports, or interactive sessions in SQL editors like Galaxy often reveal the issue.
Lingering locks stall other sessions, degrade throughput, and can lead to deadlocks. Clearing the lock or finishing the transaction frees resources and restores performance.
Automated CI/CD scripts should exit cleanly to avoid cascading failures.
Explicit table locks that are still active when a new statement requires a different lock level.
Uncommitted or unrolled-back transactions in autocommit=0 mode holding metadata locks.
Mixing transactional and non-transactional tables inside the same session without proper commit control.
Identify the blocking session with SHOW PROCESSLIST or performance_schema tables.
Confirm the State column mentions "Locked" or "Table lock".
Run COMMIT or ROLLBACK to close the transaction, or issue UNLOCK TABLES if you used LOCK TABLES.
Retry the original command once all locks are released.
Use shorter transactions or autocommit=1 to reduce future risk.
CI migrations executing ALTER TABLE after inserting seed data - wrap the seed data and the DDL in separate transactions.
ETL jobs that call LOCK TABLES for consistency - ensure UNLOCK TABLES executes in a finally block even on error.
Interactive analysis sessions in Galaxy holding BEGIN statements - Galaxy highlights open transactions, allowing a quick COMMIT.
Keep transactions small and fast; commit frequently.
Avoid LOCK TABLES unless absolutely necessary; rely on transaction isolation instead.
Configure interactive_timeout to close idle sessions that may hold locks.
Error 1205 (ER_LOCK_WAIT_TIMEOUT) occurs when a transaction waits too long on a lock held by another session.
Commit competing transactions to resolve.
Error 1213 (ER_LOCK_DEADLOCK) signals a deadlock detected. Roll back one transaction and retry.
Error 1637 (ER_LOCK_TABLE_FULL) indicates the server ran out of lock memory; tune innodb_buffer_pool_size and transaction design.
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Run SHOW PROCESSLIST or query performance_schema.data_locks to see blocking thread IDs, the table, and lock type.
No, locking is essential for consistency, but you can minimize explicit LOCK TABLES usage and keep transactions short.
Autocommit mode commits each statement automatically, greatly reducing chances but not eliminating locks from explicit LOCK TABLES.
Galaxy does not alter server behavior but warns about uncommitted transactions and lets you commit or roll back with one click.
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