All Oracle errors
ORA-03113net

End-of-file on communication channel

ORA-03113: end-of-file on communication channel

Why it happens

The server connection dropped — the database process crashed, the listener timed out, or a network device killed an idle or large session.

How to fix it

Check alert.log for an ORA- errors around the crash (often ORA-600 or memory errors), test with sqlplus from the server itself, and rule out firewalls/timeouts for long-running reports.

A note on ORA-03113

This entry is part of a hand-curated set of ORA-, FRM-, REP- and TNS- codes that actually turn up in production Oracle estates — SQL*Plus, APEX, 19c/21c, ODP.NET apps, Oracle Forms 6i/12c and Reports included. The message text above is the canonical wording; the cause and fix are written in plain language so a developer or DBA can act without digging through pages of Oracle reference docs first.

Codes outside this list of 44 are far less common. If you hit one, the official Oracle error reference and your instance's alert or listener log remain the authoritative source.

Related net errors

ORA-03114 · Not connected to ORACLE ORA-12154 · TNS cannot resolve connect identifier ORA-12514 · Listener does not know of service

Build custom software with us

From internal tools to full platforms — we deliver end to end.

Start a Project
Was this tool useful?