All errors › ORA errors
ORA-01012: Not logged on
What it means
The session no longer exists (it was killed, timed out, or the connection was lost) but the client used it.
How to fix it
Reconnect; validate pooled connections before use.
Catch it before it runs
ORA Error Helper
Explains ORA-/PLS- codes inside JetBrains IDEs and DataGrip. PL/SQL Lint
Flags risky PL/SQL patterns while you type. Oracle Plan Reader
Reads execution plans and points at the slow step. PL/SQL in Practice
Kindle book with practical PL/SQL for working developers.
Explains ORA-/PLS- codes inside JetBrains IDEs and DataGrip. PL/SQL Lint
Flags risky PL/SQL patterns while you type. Oracle Plan Reader
Reads execution plans and points at the slow step. PL/SQL in Practice
Kindle book with practical PL/SQL for working developers.
Nearby errors
Updated 2026-11-12.