Databases Reference
In-Depth Information
CHAPTER 37
■ ■ ■
ORADEBUG SQL*Plus
Command
T
he SQL*Plus command
ORADEBUG
is very useful for diagnosing performance and hanging
issues. Among other things, it may be used to verify that the correct IP addresses are used for
Real Application Clusters inter-instance communication. In releases prior to Oracle11
g
,
ORADEBUG
TRACEFILE_NAME
is the only way to determine the name of the trace file a process is writing to.
1
The manual
Oracle9i Real Application Clusters Administration Release 2
contains an
example of an
ORADEBUG
DUMP
command.
Oracle9i Database Administrator's Guide Release 2 (9.2) for
Windows
contains a section entitled “Using ORADEBUG Utility”. Yet, the information provided
is very fragmentary, since the requirement to attach to a process before running any further
commands is undocumented. In Oracle10
g
and Oracle11
g
, the only hints on the existence of
ORADEBUG
are in the
Error Messages Guide
.
Introduction to ORADEBUG
Since
ORADEBUG
is primarily intended for use by Oracle Support personnel, it has remained
largely undocumented since its introduction with SQL*Plus release 7.3. However, many
ORADEBUG
commands are very useful even for novice DBAs.
As the name suggests,
ORADEBUG
functionality serves debugging and tracing purposes.
ORADEBUG
is a SQL*Plus command, which may be entered at the SQL*Plus prompt without any
special requirements, except a connection to a DBMS instance with
SYSDBA
privileges. It may
be used to
enable SQL trace in your own server process or a foreign server process
figure out which trace file a process is writing to
dump internal ORACLE structures for diagnosing database hangs or memory corruptions
dump information from data file headers or undo segments headers
determine which shared memory segments and semaphores a DBMS instance uses
In Oracle11
g
, the column
TRACEFILE
has been added to the V$ fixed view
V$PROCESS
.
1.
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