Oradebug
Introduction
Oracle utility is called oradebug. This tool is primarily used by Oracle worldwide customer support .With oradebug utility you can literally see the database engine.
The oradebug is especially useful when things go very bad – e.g. the database just stops, hangs, or the database keeps crashing with the ORA-0600 error!
To run this tool you must have administrator privileges.
Among the many useful things that can be done with oradebug are:
– enabling/disabling the SQL tracing for another user’s session.
– suspending intensive processes
– finding information about shared memory and semaphores
– closing the trace file so that new one can be generated
– manipulating and dumping internal structures
– wake up processes etc.
HELP command
The ORADEBUG HELP command lists the commands available within ORADEBUG
These vary by release and platform. Commands appearing in this help do not necessarily work for the release/platform on which the database is running
Background Processes List
SELECT b.name, p.pid FROM gv$bgprocess b, gv$process p WHERE b.paddr = p.addr ORDER BY 1;
Dispatcher Processes List
SELECT d.name, p.pid FROM gv$dispatcher d, gv$process p WHERE d.paddr = p.addr;
Job Queue Process List
SELECT s.paddr, s.sid, j.job FROM gv$session s, dba_jobs_running j WHERE s.sid = j.sid;
SELECT pid FROM gv$process WHERE addr = ’46’;
Parallel Execution Slave Processes List
SELECT pid, server_name, status FROM gv$px_process;
Shared Server Processes List
SELECT s.name, p.pid FROM gv$shared_server s, gv$process p WHERE s.paddr = p.addr;
SGA Variables List
SELECT ksmfsnam FROM x$ksmfsv WHERE ksmfsnam LIKE ‘%\_’ ESCAPE ‘\’;
Switches
CALL
Invoke function with arguments
oradebug call [-t count] <func> [arg1]…[argn]ora
SQL> oradebug call ksmget_sgamaxalloc
CLOSE_TRACE
Close the trace file
oradebug close_trace
SQL> oradebug close_trace
CORE
Dump core without crashing process
oradebug core
SQL> oradebug core
DUMPSGA
Dump fixed SGA
oradebug dumpsga [<bytes>]
SQL> oradebug dumpsga
c:\oracle\diag\rdbms\orabase\orabase\trace\orabase_ora_2120.trc
DUMPTYPE
Print/dump an address with type info
oradebug dumptype <address> <type> <count> TBD
DUMPVAR
Print/dump a fixed PGA/SGA/UGA variable
oradebug dumpvar <pga|sga|uga> <name> [level] SQL> oradebug setmypid SQL> oradebug dumpvar SGA kcbnbh
EVENT
Set trace event in process
oradebug EVENT <event> TRACE NAME CONTEXT FOREVER, LEVEL <level> SQL> oradebug setmypid SQL> oradebug unlimit SQL> oradebug EVENT 10046 TRACE NAME CONTEXT FOREVER, LEVEL 12
FFBEGIN
Flash Freeze the Instance
oradebug ffbegin
SQL> oradebug ffbegin
FFDEREGISTER
FF deregister instance from cluster
oradebug ffderegistger
SQL> oradebug ffderegister
FFRESUMEINST
Resume a flash frozen instance
oradebug ffresumeinst
SQL> oradebug ffresumeinst
FFSTATUS
Flash freeze status of instance
oradebug ffstatus
SQL> oradebug ffstatus
FFTERMINST
Call exit and terminate instance
oradebug ffterminst
SQL> oradebug ffterminst
FLUSH
Flush pending writes to trace file
oradebug flush
SQL> oradebug flush
HANGANALYZE
Analyze system hang for stand-alone
oradebug hanganalzye [level] [syslevel] SQL> oradebug setmypid SQL> oradebug unlimit SQL> oradebug tracefile_name SQL> oradebug hanganalyze 4
Analyze system hang for RAC
SQL> oradebug setmypid SQL> oradebug -g def hanganalyze 1 SQL> oradebug flush
HELP
Describe one or all commands
oradebug help [<command>] SQL> oradebug help SQL> oradebug help flush
IPC
Dump IPC information
oradebug ipc SQL> oradebug setmypid Statement processed. SQL> oradebug ipc Information written to trace file C:\ORACLE\diag\rdbms\orabase\orabase\trace\orabase_ora_10988.trc
IPC_CHECKSUM
Enable/Disable IPC Checksumming
oradebug ipc_checksum<light/medium/full>
SQL> oradebug ipc_checksum full
IPC_TRACE
Modify IPC trace flags
oradebug ipc_trace<module> <trace_flags> <trace_level> TBD
LKDEBUG
Invoke global enqueue service debugger
oradebug lkdebug
SQL> oradebug lkdebug
MAPCOWSGA
Map SGA as COW
oradebug mapcowsga <SGA dump dir>
SQL> oradebug mapcowsga "c:\temp"
NSDBX
Invoke CGS name-service debugger
oradebug nsdbx
SQL> oradebug nsdbx
PDUMP
Invoke named dump periodically
PDUMP [interval=<interval>] [ndumps=<count>] <dump_name> <lvl> [addr] TBD
PEEK
Print/Dump memory
oradebug peek <addr> <len> [level]
SQL> oradebug peek oradebug peek 0x075731F8 12
POKE
Modify memory. Never perform this function on a production database!
oradebug poke <addr> <len> <value>
SQL> oradebug poke 0x20005F0C 4 0x46495845
PROCSTAT
Dump process statistics oradebug procstat
SQL> oradebug setmypid SQL> oradebug procstat
SQL> select pid,name from v$process p, v$bgprocess b where b.paddr = p.addr;
SQL>
PID NAME
-- -----
2 PMON
3 CLMN
4 PSP0
5 VKTM
6 GEN0
7 MMAN
8 OFSD
9 GEN1
10 SCMN
11 DIAG
12 SCMN
PID NAME
-- -----
13 DBRM
14 VKRM
15 SVCB
16 PMAN
17 DIA0
18 DBW0
19 LGWR
20 CKPT
21 SMON
22 SMCO
23 RECO
PID NAME
-- -----
24 W001
25 LREG
27 PXMN
28 FENC
29 MMON
30 MMNL
32 TMON
33 W003
34 TT00
35 ARC0
36 TT01
PID NAME
-- -----
37 ARC1
38 ARC2
39 ARC3
40 TT02
41 AQPC
42 W005
43 QM02
44 W007
45 W000
46 Q003
47 CJQ0
PID NAME
-- -----
49 Q002
54 W004
55 W006
47 rows selected.
SQL>
RESUME
Resume execution oradebug resume
SQL> oradebug resume
SESSION_EVENT
Set trace event in session
oradebug session_event <text>
SQL> oradebug session_event 10053 TRACE NAME CONTEXT FOREVER, LEVEL 1
SETINST
Set instance list
oradebug setinst <instance# .. | all>
SQL> oradebug setinst "1"
SETMYPID
Sets the oradebug PID to the current process
oradebug setmypid
SQL> oradebug setmypid
SETORAPID
Set PID of Oracle process to debug
oradebug setorapid <orapid> ['force']
SETORAPNAME
Set Oracle process name to debug
oradebug setorapname <orapname>
SETOSPID
Set OS pid of process to debug. The operating system process ID is the PID on Unix systems and the thread number for Windows systems
oradebug setospid <ospid> Do not use as it often fails. Use setorapid instead.
SETTRACEFILEID
Set tracefile identifier oradebug settracefileid <identifier name>
SQL> oradebug settracefileid odebug
SETVAR
Modify a fixed PGA/SGA/UGA variable
oradebug setvar <pga|sga|uga> <name> <value> SQL> oradebug setvar SGA kcfdfk 200
SGATOFILE
Dump SGA to file oradebug sgatofile <SGA dump dir>
SQL> oradebug ffbegin SQL> oradebug sgatofile "c:\temp" SQL> oradebug ffresumeinst
SHORT_STACK
Get abridged OS stack
oradebug short_stack
SQL> oradebug short_stack
SHOW
Show watchpoints
oradebug show <local|global|target> watchpoint <id>
SQL> oradebug show global watchpoints
SKDSTTPCS
Helps translate PCs to names
oradebug skdsttpcs <ifname> <ofname> TBD
SUSPEND
Suspends the current process
oradebug suspend
SQL> oradebug suspend
TRACEFILE_NAME
Get trace file name
Will not return a value on Windows systems
oradebug tracefile_name
SQL> oradebug tracefile_name
UNLIMIT
Unlimit the size of the trace file
oradebug unlimit
SQL> oradebug unlimit
WAKEUP
Wake up Oracle process
oradebug wakeup <orapid>
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