Oracle database housekeeping methods – ADR files purge

Since Oracle Database 11g, all traces, incident dumps and packages, the alert log, Health Monitor reports, core dumps, and more files are stored in the ADR, a file-based Automatic Diagnostic Repository for simplified database diagnostic data management. In spite of that new 11g feature, the housekeeping or purging of those files got not considerably simplified. Unfortunately the new Oracle utility ADRCI can not purge all the files that Oracle database generates in ADR. Thus, you should use the other Unix OS methods and tools to accomplish Oracle 11g database housekeeping. In previous posts I described the Unix log rotation mechanism and SYS auditing files purge in adump directory. This time we will talk exactly about ADR purge functionality. But before, let’s look at some basics.

Location for Diagnostic Traces

Location of Diagnostic Traces of Oracle ADR

Location of Diagnostic Traces in Oracle 11g ADR

The table shown above in the slide describes the different classes of trace data and dumps that reside both in Oracle Database 10g and 11g.
With Oracle Database 11g, there is no distinction between foreground and background trace files. Both types of files go into the $ADR_HOME/trace directory.
All non-incident traces are stored inside the trace subdirectory. This is the main difference compared with previous releases where critical error information is dumped into the corresponding process trace files instead of incident dumps. Incident dumps are placed in files separated from the normal process trace files starting with Oracle Database 11g. We can also check V$DIAG_INFO view lists all important ADR locations including.

ADR retention policy – automatic purge

A retention policy allows you to specify how long to keep the diagnostic data. ADR incidents are controlled by two different policies:

The incident metadata retention policy controls how long the metadata is kept around. This policy has a default setting of one year (default is 8760 = 365 days = 1 year). Here are the components that currently get purged by LONGP_POLICY:

ALERT — files in the ./alert directory
INCIDENT – files in the ./incident/incdir_ directory.
SWEEP — files in the ./sweep directory
STAGE — files in the ./stage directory
HM — files in the ./hm directory and metadata in the HM schema

The incident files and dumps retention policy controls how long generated dump files are kept around. This policy has Read more »

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