Before using ORADEBUG commands, a process must be selected. Depending on the commands to be issued, this can either be the current process or another process Once a process has been selected, this will be used as the ORADEBUG process until another process is selected The SETMYPID command selects the current process as the ORADEBUG process For example ORADEBUG SETMYPIDORADEBUG SETMYPID can be used to select the current process to run systemwide commands such as dumps Do not use ORADEBUG SETMYPID if you intend to use the ORADEBUG SUSPEND command

SETORAPID command

Before using ORADEBUG commands, a process must be selected. Depending on the commands to be issued, this can either be the current process or another process Once a process has been selected, this will be used as the ORADEBUG process until another process is selected The SETORAPID command selects another process using the Oracle PID as the ORADEBUG process The syntax is ORADEBUG SETORAPID [i]pidwhere [i]pid is the Oracle process ID of the target process For example
ORADEBUG SETORAPID 9The Oracle process id for a process can be found in V$PROCESS.PID To obtain the Oracle process ID for a foreground process use SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$session WHERE sid = DBMS_SUPPORT.MYSID );Alternatively, if the DBMS_SUPPORT package is not available use
SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$session WHERE sid = ( SELECT sid FROM v$mystat WHERE ROWNUM = 1 ) );To obtain the process ID for a background process e.g. SMON use
SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$bgprocess WHERE name = 'SMON' );To obtain the process ID for a dispatcher process e.g. D000 use
SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$dispatcher WHERE name = 'D000' );To obtain the process ID for a shared server process e.g. S000 use
SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$shared_server WHERE name = 'S000' );To obtain the process ID for a job queue process e.g. job 21 use
SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$session WHERE sid = ( SELECT sid FROM dba_jobs_running WHERE job = 21 ) );To obtain the process ID for a parallel execution slave e.g. P000 use
SELECT pid FROM v$px_process WHERE server_name = 'P000';

SETOSPID command

Before using ORADEBUG commands, a process must be selected. Depending on the commands to be issued, this can either be the current process or another process Once a process has been selected, this will be used as the ORADEBUG process until another process is selected The SETOSPID command selects the another process using the operating system PID as the ORADEBUG process The syntax is ORADEBUG SETOSPID [i]pidwhere [i]pid is the operating system process ID of the target process For example
ORADEBUG SETOSPID 34345The operating system process ID is the PID on Unix systems and the thread number on Windows NT/2000 systems On Unix the PID of interest may have been identified using a [i]top or [i]ps command

TRACEFILE_NAME command

This command prints the name of the current trace file e.g. ORADEBUG TRACEFILE_NAMEFor example /export/home/admin/SS92003/udump/ss92003_ora_14917.trcThis command does not work on Windows 2000 (Oracle 9.2)

UNLIMIT command

In Oracle 8.1.5 and below the maximum size of the trace file is restricted by default. This means that large dumps (LIBRARY_CACHE, BUFFERS) may fail. To remove the limitation on the size of the trace file use ORADEBUG UNLIMITIn Oracle 8.1.6 and above the maximum size of the trace file defaults to UNLIMITED

FLUSH command

To flush the current contents of the trace buffer to the trace file use ORADEBUG FLUSH

CLOSE_TRACE command

To close the current trace file use ORADEBUG CLOSE_TRACE

SUSPEND command

This command suspends the current process First select a process using SETORAPID or SETOSPID Do not use SETMYPID as the current ORADEBUG process will hang and cannot be resumed even from another ORADEBUG process For example the command ORADEBUG SUSPENDsuspends the current process
The command ORADEBUG RESUMEresumes the current process
While the process is suspended ORADEBUG can be used to take dumps of the current process state e.g. global area, heap, subheaps etc. This example demonstrates how to take a heap dump during a large (sorting) query This example requires two sessions, session 1 logged on SYS AS SYSDBA and session 2 which executes the query. In session 2 identify the PID using SELECT pid FROM v$process WHERE addr IN ( SELECT paddr FROM v$session WHERE sid = dbms_support.mysid );In this example the PID was 12 In session 1 set the Oracle PID using ORADEBUG SETORAPID 12In session 2 start the query SELECT ... FROM t1 ORDER BY ....In session 1 suspend session 2 ORADEBUG SUSPENDThe query in session 2 will be suspended In session 1 run the heap dump ORADEBUG DUMP HEAPDUMP 1The heapdump will show the memory structures allocated for the sort. At this point further dumps e.g. subheap dumps can be taken. In session 1 resume session 2 ORADEBUG RESUMEThe query in session 2 will resume execution

RESUME command

This command resumes the current process First select a process using SETORAPID or SETOSPID Do not use SETMYPID as the current ORADEBUG process will hang and cannot be resumed even from another ORADEBUG process For example the command ORADEBUG SUSPENDsuspends the current process
The command ORADEBUG RESUMEresumes the current process
While the process is suspended ORADEBUG can be used to take dumps of the current process state e.g. global area, heap, subheaps etc. See SUSPEND for an example of use of the SUSPEND and RESUME commands

WAKEUP command

To wake up a process use ORADEBUG WAKEUP [i]pidFor example to wake up SMON, first obtain the PID using SELECT pid FROM v$process WHERE addr = ( SELECT paddr FROM v$bgprocess WHERE name = 'SMON' );If the PID is 6 then send a wakeup call using ORADEBUG WAKEUP 6

DUMPLIST command

To list the dumps available in ORADEBUG use ORADEBUG DUMPLIST [i]pidFor example in Oracle 9.2 (Windows 2000) this command returns the following

[td=50]
Dump Name
EVENTS
TRACE_BUFFER_ON
TRACE_BUFFER_OFF
HANGANALYZE
LATCHES
PROCESSSTATE
SYSTEMSTATE
INSTANTIATIONSTATE
REFRESH_OS_STATS
CROSSIC
CONTEXTAREA
HEAPDUMP
HEAPDUMP_ADDR
POKE_ADDRESS
POKE_LENGTH
POKE_VALUE
POKE_VALUE0
GLOBAL_AREA
MEMORY_LOG
REALFREEDUMP
ERRORSTACK
HANGANALYZE_PROC
TEST_STACK_DUMP
BG_MESSAGES
ENQUEUES
SIMULATE_EOV
KSFQP_LIMIT
KSKDUMPTRACE
DBSCHEDULER
GRANULELIST
GRANULELISTCHK
SCOREBOARD
GES_STATE
ADJUST_SCN
NEXT_SCN_WRAP
CONTROLF
FULL_DUMPS
BUFFERS
RECOVERY
SET_TSN_P1
BUFFER
PIN_BUFFER
BC_SANITY_CHECK
FLUSH_CACHE
LOGHIST
ARCHIVE_ERROR
REDOHDR
LOGERROR
OPEN_FILES
DATA_ERR_ON
DATA_ERR_OFF
BLK0_FMTCHG
TR_SET_BLOCK
TR_SET_ALL_BLOCKS
TR_SET_SIDE
TR_CRASH_AFTER_WRITE
TR_READ_ONE_SIDE
TR_CORRUPT_ONE_SIDE
TR_RESET_NORMAL
TEST_DB_ROBUSTNESS
LOCKS
GC_ELEMENTS
FILE_HDRS
KRB_CORRUPT_INTERVAL
KRB_CORRUPT_SIZE
KRB_PIECE_FAIL
KRB_OPTIONS
KRB_SIMULATE_NODE_AFFINITY
KRB_TRACE
KRB_BSET_DAYS
DROP_SEGMENTS
TREEDUMP
LONGF_CREATE
ROW_CACHE
LIBRARY_CACHE
SHARED_SERVER_STATE
KXFPCLEARSTATS
KXFPDUMPTRACE
KXFPBLATCHTEST
KXFXSLAVESTATE
KXFXCURSORSTATE
WORKAREATAB_DUMP
OBJECT_CACHE
SAVEPOINTS
OLAP_DUMP

DUMP command

To perform. a dump use ORADEBUG DUMP [i]dumpname [i]levelFor example for a level 4 dump of the library cache use ORADEBUG SETMYPID ORADEBUG DUMP LIBRARY_CACHE 4

EVENT command

To set an event in a process use ORADEBUG EVENT [i]event TRACE NAME CONTEXT FOREVER, LEVEL [i]levelFor example to set event 10046, level 12 in Oracle process 8 use ORADEBUG SETORAPID 8 ORADEBUG EVENT 10046 TRACE NAME CONTEXT FOREVER, LEVEL 12

SESSION_EVENT command

To set an event in a session use ORADEBUG SESSION_EVENT [i]event TRACE NAME CONTEXT FOREVER, LEVEL [i]levelFor example ORADEBUG SESSION_EVENT 10046 TRACE NAME CONTEXT FOREVER, LEVEL 12

DUMPSGA

To dump the fixed SGA use ORADEBUG DUMPSGA

DUMPVAR

To dump an SGA variable use ORADEBUG DUMPVAR SGA [i]variable_namee.g. ORADEBUG DUMPVAR SGA kcbnhbwhich returns the number of hash buckets in the buffer cache The names of SGA variables can be found in X$KSMFSV.KSMFSNAM. Variables in this view are suffixed with an underscore e.g. kcbnhb_

PEEK

To peek memory locations use ORADEBUG PEEK [i]address [i]lengthwhere address can be decimal or hexadecimal and length is in bytes For example ORADEBUG PEEK 0x20005F0C 12returns 12 bytes starting at location 0x20005f0c

POKE

To poke memory locations use ORADEBUG POKE [i]address [i]length [i]valuewhere address and value can be decimal or hexadecimal and length is in bytes For Example ORADEBUG POKE 0x20005F0C 4 0x46495845 ORADEBUG POKE 0x20005F10 4 0x44205349 ORADEBUG POKE 0x20005F14 2 0x5A45WARNING Do not use the POKE command on a production system

IPC

To dump information about operating system shared memory and semaphores configuration use the command ORADEBUG IPCThis command does not work on Windows NT or Windows 2000 (Oracle 9.2) On Solaris, similar information can be obtained using the operating system command ipcs -b

Dumping the SGA

In some versions it is possible to dump the entire SGA to a file Freeze the instance using ORADEBUG FFBEGINDump the SGA to a file using ORADEBUG SGATOFILE [i]directoryUnfreeze the instance using ORADEBUG FFRESUMEINSTThis works in Oracle 9.0.1 and 9.2.0 on Solaris, but fails in both versions in Windows 2000