Sunday , October 22 2017
Home / Oracle DBA / Overview of Diagnostic Files

Overview of Diagnostic Files

Overview of Diagnostic Files

Oracle Database includes a fault diagnosability infrastructure for preventing, detecting, diagnosing, and resolving database problems. Problems include critical errors such as code bugs, metadata corruption, and customer data corruption. The goals of the advanced fault diagnosability infrastructure are the following:
  • Detecting problems proactively
  • Limiting damage and interruptions after a problem is detected
  • Reducing problem diagnostic and resolution time
  • Simplifying customer interaction with Oracle Support

Automatic Diagnostic Repository

Automatic Diagnostic Repository (ADR) is a file-based repository that stores database diagnostic data such as trace files, the alert log, and Health Monitor reports. Key characteristics of ADR include:
  • Unified directory structure
  • Consistent diagnostic data formats
  • Unified tool set
ADR is located outside the database, which enables Oracle Database to access and manage ADR when the physical database is unavailable. An instance can create ADR before a database has been created.

Problems and Incidents

ADR proactively tracks problems, which are critical errors in the database. Critical errors manifest as internal errors, such as ORA-600, or other severe errors. Each problem has a problem key, which is a text string that describes the problem. When a problem occurs multiple times, ADR creates a time-stamped incident for each occurrence. An incident is uniquely identified by a numeric incident ID. When an incident occurs, ADR sends an incident alert to Enterprise Manager. Diagnosis and resolution of a critical error usually starts with an incident alert. Because a problem could generate many incidents in a short time, ADR applies flood control to incident generation after certain thresholds are reached. A flood-controlled incident generates an alert log entry, but does not generate incident dumps. In this way, ADR informs you that a critical error is ongoing without overloading the system with diagnostic data.
View More:
Automatic Undo Retention
Undo Table spaces
Overview of Table spaces



Check Also

Moving a database from Normal File System to ASM storage

Default storage for oracle database is File System, where database files resides on local storage. …

Leave a Reply

Your email address will not be published. Required fields are marked *