Oracle Database / Sessions, Locks & Transactions
ORA-00028: investigate why a session was terminated
A session-killed error can follow an administrator action, resource enforcement or another managed operation. Preserve the time and account context.
Environment and inputs: Oracle Database 19c baseline · SQL*Plus-compatible SQL unless RMAN, DGMGRL, ADRCI or a host shell is specified. Check release, patch level, edition and container first.
Start with this diagnostic
Use the stated SQL, RMAN, DGMGRL or host shell and replace sample names with approved targets. DBA and V$ views need authorized catalog access in the correct container. Do not grant broad privileges for an example.
SELECT sid, serial#, username, status, service_name FROM v$session WHERE username = 'APP_USER';Read the result
Remaining sessions describe current state only. The terminated session may already have disappeared, so this query cannot establish who ended it.
Resolve and verify
Correlate available audit, administrator change and application logs. Repair the pool's handling of dead connections and confirm whether unfinished work requires rollback or business reconciliation.
Operational precautions
Do not assume a disconnected transaction committed or that the same SID now represents the original session.