About Database Problems and Incidents

To help diagnosis and resolution of critical errors, Oracle Database Release 11g introduces two concepts for Oracle Database: problems and incidents.

A problem is a critical error in the database. Critical errors manifest as internal errors, such as ORA-00600, and other severe errors, such as ORA-07445 (operating system exception) or ORA-04031 (out of memory in the shared pool portion). Problems are tracked in the Automatic Diagnostic Repository (ADR). The ADR is a file-based repository for storing diagnostic data. Because this repository is stored outside the database, the diagnostic data is available even when the database is down. As of Release 11g, the alert log, all trace and dump files, and other diagnostic data are also stored in the ADR.

Each problem has a problem key, which is a text string that describes the problem. The problem key includes the error code (such as ORA 600), and in some cases, one or more error parameter values or other information.

An incident is a single occurrence of a problem. When a problem occurs multiple times, an incident is created for each occurrence. Incidents are timestamped and tracked in the Automatic Diagnostic Repository (ADR).

Each incident is identified by a numeric incident ID, which is unique within the ADR. When an incident occurs, the database performs the following steps:

• Makes an entry in the alert log.

• Sends an incident alert to Enterprise Manager.

• Gathers first-failure diagnostic data about the incident (such as trace files).

• Tags the diagnostic data with the incident ID.

• Stores the data in an ADR subdirectory created for that incident.

Each incident has a problem key and is mapped to a single problem.

Diagnosis and resolution of a critical error usually starts with an incident alert. The incident alert is displayed on the Enterprise Manager Database Home page. You can then view the problem and its associated incidents with Enterprise Manager.