Problem Diagnosis - Expert Oracle RAC Performance Diagnostics and Tuning - page 611

Like most utilities and tools, Oracle provides two types of interfaces to query the ADR: command line interface
using adrci or using EM.

ADR Actions
The ADR is a file-based repository for database diagnostic data such as traces, dumps, the alert log, HM reports, and
more. It has a unified directory structure across multiple instances and multiple products. The Oracle database, ASM,
and other Oracle products or components store all diagnostic data in the ADR. ADR uses an internal methodology
(illustrated in Figure 18-5 ) to manage these diagnostic data and consists of the actions described following.

Problem
problem ID

Critical error

Incident Status
Collecting
Ready
Tracking
Data purged
Closed

DBA

Incident
Incident ID

MMON

Non critical errors

Package to be sent
To Oracle Support

Incident Data Retention period

Figure 18-5. Incident tracking process flow

Problem
ADR is used to track problems. Each problem has a problem key and a unique problem ID that is a sequence number
to the problems reported in the ADR. An example of a problem could be a critical error generated by the database
such as an ORA-600 error.

Incident
An incident is a single occurrence of a problem. When a problem occurs multiple times, an incident is created for
each occurrence. When an incident occurs, the database makes an entry in the alert log, sends an incident alert to EM,
gathers diagnostic data about the incident in the form of dump files (incident dumps), tags the incident dumps with
the incident ID, and stores the incident dumps in an ADR subdirectory created for that incident.