RAC MEMORY STRUCTURES

1 © 2006 Julian Dyke
Inside
RAC
Julian Dyke
Independent Consultant
Web Version
juliandyke.com

© 2006 Julian Dyke juliandyke.com2
Agenda
 Introduction to RAC
 Memory Structures
 The Buffer Cache
 Global Cache Services
 The Library Cache
 Global Enqueue Services

Introduction
to
RAC

What is RAC?
 Multiple instances running on separate servers (nodes)
 Single database on shared storage accessible to all nodes
 Instances exchange information over an interconnect network
Node 1
Instance 1
Node 2
Instance 2Interconnect
Shared
Storage
Local
Disk
Local
Disk

Architecture
Instance 1
Node 1
Instance 2
Node 2
Shared
Storage
Storage Network
Private Network
(Interconnect)
Public Network

Some Definitions
 Resource
 Object to which access must be controlled at instance
level
 Enqueue
 Memory structure that serializes access to a resource
 Global Resources
 Object to which access must be controlled at cluster level
 Global Enqueue
 Locks and enqueues which need to be consistent between
all instances

Some Definitions...
 Global Resource Directory (GRD)
 Records current state and owner of each resource
 Contains convert and write queues
 Distributed across all instances in cluster
 Maintained by GCS and GES
 Global Cache Services (GCS)
 Implements cache coherency for database
 Coordinates access to database blocks for instances
 Global Enqueue Services (GES)
 Controls access to other resources (locks) including
library cache and dictionary cache
 Performs deadlock detection

Instance 2Instance 1
Background Processes
DIAG
LMON
LCK
LMD
LMS
LGWR
SMONPMON
CKPT
ARCH
DIAG
LMON
LCK
LMD
LMS
CKPT
ARCH
LGWR
PMON
DBWR
SMON
DBWR
Redo Logs
Datafiles
Controlfiles
Redo Logs
SGAUGASGA UGA

 LMSn
 Global Cache Service Process
 Manage requests for data access across cluster
 Up to 20 in Oracle 10.1
 LMS0-LMS9 LMSa-LMSj
 Up to 36 in Oracle 10.2
 LMS0-LMS9 LMSa-LMSz
 In Oracle 10.1 and above, number of GCS server processes
can be configured using gcs_server_processes parameter
 Default value is 1 (single CPU system)

 LCK0
 Instance Enqueue Process
 Manages
 instance resource requests
 cross-instance call operations
 Assists LMS processes
 Formerly known as lock process
 In 9.0.1 and below, number of lock processes may be
configurable using _gc_lck_procs parameter

 LMD0
 Global Enqueue Service Daemon
 Manages requests for global enqueues
 Updates status of enqueues when granted to / revoked
from an instance
 One LMD0 process per instance
 In 8.1.7 and below number of lock daemons may be
configurable using _lm_dlmd_processes parameter

 LMON
 Global Enqueue Service Monitor
 One LMON process per instance
 Monitors cluster to maintain global enqueues and
resources
 Manages
 instance and process expirations
 recovery processing for cluster enqueues

 DIAG - Diagnosibility Process
 Collects diagnostic data in the event of a failure
 Creates subdirectories in BACKGROUND_DUMP_DEST
directory
 In Oracle 9.0.1 and above can be disabled using
_diag_daemon parameter
 Do not try this on a production system

Fixed Tables
 Memory structures externalized in X$ tables
 Instance specific
 Underlying structures for dynamic performance views
 Can contain
 Structures accessed directly from executable
 X$KSLLD => V$LATCHNAME
 X$KSUSD => V$STATNAME
 Structures accessed directly from SGA
 X$KSUSE => V$SESSION
 X$KSUPR => V$PROCESS
 Executable and/or SGA structures joined in PGA
 X$KQLFXPL => V$SQL_PLAN
 X$KGLOB => V$SQL, V$SQL_AREA

Dynamic Performance Views
 In a RAC environment each V$ view has an equivalent GV$
view
 GV$ view includes INST_ID column. For example
 V$SGA
NAME VARCHAR2(20)
VALUE NUMBER
 GV$SGA
INST_ID NUMBER
NAME VARCHAR2(20)
VALUE NUMBER
 In Oracle 9.2 and below PARALLEL_MIN_SERVERS must be
>= number of hosts to use GV$ views
 In Oracle 10.1 and above PZnn background processes are
used to return data on remote hosts e.g. PZ99

CATCLUST.SQL
 Some additional views/synonyms are created for RAC
databases using $ORACLE_HOME/rdbms/admin/catclust.sql
Synonym Name View Name
V$GES_CONVERT_LOCAL V$DLM_CONVERT_LOCAL
V$GES_CONVERT_REMOTE V$DLM_CONVERT_REMOTE
V$GES_LATCH V$DLM_LATCH
V$GES_RESOURCE V$DLM_RESS
V$GES_STATISTICS V$DLM_MISC
V$GES_TRAFFIC_CONTROLLER V$DLM_TRAFFIC_CONTROLLER
GV$GES_CONVERT_LOCAL GV$DLM_CONVERT_LOCAL
GV$GES_CONVERT_REMOTE GV$DLM_CONVERT_REMOTE
GV$GES_LATCH GV$DLM_LATCH
GV$GES_RESOURCE GV$DLM_RESS
GV$GES_STATISTICS GV$DLM_MISC
GV$GES_TRAFFIC_CONTROLLER GV$DLM_TRAFFIC_CONTROLLER

ORADEBUG
 ORADEBUG includes LKDEBUG
 Must be run by user with SYSDBA privilege
SQL> ORADEBUG LKDEBUG HELP
Usage:lkdebug [options]
-l [r|p] <enqueue pointer> Enqueue Object
-r <resource pointer> Resource Object
-b <gcs shadow pointer> GCS shadow Object
-p <process id> client pid
-P <process pointer> Process Object
-O <i1> <i2> <types> Oracle Format resname
-a <res/lock/proc> all <res/lock/proc> pointer
-A <res/lock/proc> all <res/lock/proc> contexts
-a <res> [<type>] all <res> pointers by an optional type
-a convlock all converting enqueue (pointers)
-A convlock all converting enqueue contexts
-a convres all res ptr with converting enqueues
-A convres all res contexts with converting enqueues

ORADEBUG
 Continued...
-a name list all resource names
-a hashcount list all resource hash bucket counts
-t Traffic controller info
-s summary of all enqueue types
-k GES SGA summary info
-m pkey <objectno> request for remastering this object at current instance
-m dpkey <objectno> request for dissolving remastering of this object at
current instance

Memory
Structures

Memory Areas
 An Oracle process includes
the following memory areas
 Executable
 SGA
 Shared Libraries
 PGA/Session Heap
 Stack
40000000
20000000
Executable
PGA
Session Heap
Shared
Libraries
SGA
Stack
STOP
FFFFFFFF
00000000

Shared Memory
 Shared memory areas can be dumped to trace file using
ORADEBUG SETMYPID
ORADEBUG IPC
$ sqlplus /nolog
SQL> CONNECT SYS/<password> AS SYSDBA
Connected
SQL> ORADEBUG SETMYPID
Statement processed
SQL> ORADEBUG IPC
Information written to trace file

Area #0 `Fixed Size' containing Subareas 0-0
Total size 0000000000129968 Minimum Subarea size 00000000
Area Subarea Shmid Stable Addr Actual Addr
0 0 65537 0x00000020000000 0x00000020000000
Subarea size Segment size
000000000012a000 0000000010800000
Area #1 `Variable Size' containing Subareas 2-2
1 2 65537 0x00000020400000 0x00000020400000
0000000010000000 0000000010800000
Area #2 `Redo Buffers' containing Subareas 1-1
Total size 00000000002d6000 Minimum Subarea size 00000000
Area Subarea Shmid Stable Addr Actual Add
2 1 65537 0x0000002012a000 0x0000002012a000
00000000002d6000 0000000010800000
Area #3 `skgm overhead' containing Subareas 3-3
3 3 65537 0x00000030400000 0x00000030400000
0000000000001000 0000000010800000
ORADEBUG IPC - Example
STOP
Area #0 `Fixed Size' containing Subareas 0-0
0 0 65537 0x00000020000000 0x00000020000000
000000000012a000 0000000010800000
Area #1 `Variable Size' containing Subareas 2-2
1 2 65537 0x00000020400000 0x00000020400000
0000000010000000 0000000010800000
Area #2 `Redo Buffers' containing Subareas 1-1
Total size 00000000002d6000 Minimum Subarea size 00000000
Area Subarea Shmid Stable Addr Actual Add
2 1 65537 0x0000002012a000 0x0000002012a000
00000000002d6000 0000000010800000
Area #3 `skgm overhead' containing Subareas 3-3
3 3 65537 0x00000030400000 0x00000030400000
0000000000001000 0000000010800000
Fixed Area
Variable Area
Redo Buffers
OS Specific

Shared Global Area
 Contains
 Fixed SGA
 Buffer Pool
 Shared Pool Oracle 7.0 and above
 Large Pool Oracle 8.0 and above
 Java Pool Oracle 8.1.5 and above
 Streams Pool Oracle 10.1 and above
 Redo buffers
 Buffer Pool includes
 Default cache
 Keep and Recycle cache Oracle 8.0 and above
 2K, 4K, 8K, 16K and 32K cache Oracle 9.0.1 and above

V$SGAINFO
 Summarizes SGA pools
NAME VARCHAR2(32)
BYTES NUMBER
RESIZEABLE VARCHAR2(3)
SELECT * FROM v$sgainfo;
NAME BYTES RESIZEABLE
-------------------------------- ---------- ----------
Fixed SGA Size 1218920 No
Redo Buffers 2973696 No
Buffer Cache Size 176160768 Yes
Shared Pool Size 83886080 Yes
Large Pool Size 4194304 Yes
Java Pool Size 4194304 Yes
Streams Pool Size 0 Yes
Granule Size 4194304 No
Maximum SGA Size 272629760 No
Startup overhead in Shared Pool 46137344 No
Free SGA Memory Available 0

Granules
 Introduced in Oracle 9.0.1
 SGA divided into granules
 In Oracle 9.2 Unix granule size dependent on SGA_MAX_SIZE
 4 mb SGA_MAX_SIZE <= 128 mb
 16 mb SGA_MAX_SIZE > 128 mb
 If SGA_MAX_SIZE not set explicitly then defaults to sum of
individual pool parameters
 SGA_MAX_SIZE cannot be dynamically modified

Granules
 In Oracle 10.1 and above
 SGA_MAX_SIZE dependent on SGA_TARGET
 Granule size dependent on SGA_MAX_SIZE
 4 mb SGA_MAX_SIZE <= 256 mb??
 16 mb SGA_MAX_SIZE > 256 mb ??
 Granule size can be controlled using _ksmg_granule_size
unsupported parameter

X$KSMGE
Introduced in Oracle 9.2
Describes individual granules
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
GRANNUM NUMBER
GRANTYPE NUMBER
GRANSTATE VARCHAR2(16)
GRANFLAGS NUMBER
LOCALITY NUMBER
KSMAREANUM NUMBER
BASEADDR RAW(4)
GRANSIZE NUMBER
GRANNEXT NUMBER
GRANPREV NUMBER
INVALID (Free)
ALLOCATED
Granule Address
Granule Size
Next granule ID
Previous granule ID
Granule ID
0 Free
1 Shared Pool
2 Large Pool
3 Java Pool
6 Buffer Pool

Granules
SGA_TARGET = 260M
SGA_MAX_SIZE = 260M
GRANULE SIZE = 4M
256M
4M
Buffer Pool 172M
Fixed SGA + Redo
Buffers 4M
Large Pool 4M
Shared Pool 76M
Java Pool 4M
STOP
This is an example of an
SGA mapped using
X$KSMGE

V$SGASTAT
 Enhanced in Oracle 10.1 and above
Shared Pool 682
Large Pool 6
Java Pool 4
Streams Pool 4
 In Oracle 10.2 describes around 700 memory areas
POOL VARCHAR2(12)
NAME VARCHAR2(26)
BYTES NUMBER

V$SGASTAT
 RAC-specific areas include
gcs affinity
gcs close obj
gcs commit sga state
gcs I/O statistics struct
gcs mastership buckets
gcs opaque in
gcs res hash bucket
gcs res latch table
gcs resource freelist arr
gcs resource freelist dyn
gcs resources
gcs scan queue array
gcs shadow locks dyn seg
gcs shadow locks freelist
gcs shadows
ges big msg buffers
ges deadlock xid freelist
ges deadlock xid hash tab
ges enqueue cur. usage pe
ges enqueue max. usage pe
ges enqueue multiple free
ges enqueues
ges ipc instance maps
ges lmd process descripto
ges lms process descripto
ges process array
ges process hash table
ges recovery domain table
ges regular msg buffers
ges reserved msg buffers
ges res mastership bucket
ges resource
ges resource hash seq tab
ges resource hash table
ges resource pools
ges scan queue array
ges shared global area
KCL buffer header
KCL instance cache transf
KCL lock contexts
KCL lock state
KCL name table
KCL partition table
KCL region array
KJXM msg statistics table

V$SGASTAT
 Significant RAC areas in Oracle 10.2
Name Size(bytes) Location
gcs resources 2298008 Segmented Array
gcs shadows 1632280 Segmented Array
ges resource 1257188 Heap
ges enqueues 1625344 Segmented Array
ges big msg buffers 3979396 Unknown
 In Oracle 9.2 all five structures were stored in segmented
arrays

Permanent Areas
SELECT ksmchptr, ksmchsiz
FROM x$ksmsp
WHERE ksmchcls = 'perm';
Address Size
2D034000 3981312
2D434000 3549424
2D834000 3963236
2DC34000 3980584
2DFFFD28 728
2E034000 3919532
 Allocated at instance startup
 Contain structures such as
 processes
 sessions
 segmented arrays
STOP
2AC00000
2B800000
2BC00000
2C000000
2C400000
2C800000
2CC00000
2D000000
2D800000
2DC00000
2E000000
2E400000
2E800000
2EF00000
2F000000
2F400000
2F800000
2FC00000
30000000
2D400000
Permanent
Area
Heap

X$KSMSP
 Externalises chunks in the shared pool
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KSMCHIDX NUMBER
KSMCHDUR NUMBER
KSMCHCOM VARCHAR2(16)
KSMCHPTR RAW(4)
KSMCHSIZ NUMBER
KSMCHCLS VARCHAR2(8)
KSMCHTYP NUMBER
KSMCHPAR RAW(4)
Description of chunk type
Address of chunk
Size including header
Class
●Perm
●Recreate
●Freeable
●Free
●R-Free
●R-Freeable
Address of parent
Type (recreate only)
●0x18 - KGL Handle
●0x24 - Fixed Allocation
●0x74 - KQR PO
●0x80 - KQR SO
●0xFFF - Extended header

X$KSMSP
 Some RAC components are stored in the shared pool heap
SELECT ksmchcom, SUM(ksmchsiz), COUNT(*)
FROM x$ksmsp
GROUP BY ksmchcom;
gcs_mastership 4620 1
gcs_res_hash_bu 16396 1
gcs_res_latch_t 7692 1
ges_res_masters 3084 1
ges_resource 619276 164

Segmented Arrays
 Used to store arrays of objects
 Array too large to fit in granule
 Array may grow dynamically
 Objects using segmented arrays include
 enqueues (locks)
 enqueue resources (resources)
 transactions
 transaction branches
 Segmented arrays managed recursively by segmented array
 Segmented arrays externalised in X$KSMDD

Segmented Arrays
Segmented
Arrays
Call
Enqueues
Enqueue
Resources
Segmented
Array
Header
Segmented
Array
Segmented
Array
Header
Segmented
Array
STOP

X$KSMDD
 Externalises segmented array headers
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
NAME VARCHAR2(30)
ELEMENTS_CHUNK NUMBER
ITEMS_PT NUMBER
INITENTRIES NUMBER
NUMENTRIES NUMBER
CURENTRIES NUMBER
NUMCHUNKS NUMBER
ELEMSIZE NUMBER
FLAGS NUMBER
HEAP RAW(4)
SECONDARY RAW(4)
Name of array
Address of parent
heap
Number of
chunks

Segmented Arrays
 In Oracle 10.2 there are three RAC-specific segmented arrays:
 GCS Resources
 GCS Shadows
 GES Enqueues
 In previous releases there were five segmented arrays:
 GCS Resources
 GCS Shadows
 GES Resources
 GES Shadows
 GES Messages

Heaps
 A heap consists of one or more extents
 Each heap extent occupies a single granule
 Each extent contains one or more chunks
 Each heap has a header containing
 list of used chunks
 list of free chunks
Extent 0 Extent 1 Extent 2Heap
Header
Free List Chunks
STOP

X$KSMHP
 Externalises chunks in the heap
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KSMCHDS RAW(4)
KSMCHCOM VARCHAR2(16)
KSMCHPTR RAW(4)
KSMCHSIZ NUMBER
KSMCHCLS VARCHAR2(8)
KSMCHTYP NUMBER
KSMCHPAR RAW(4)
KSMCHOWN RAW(4)
 Can only be accessed using KSMCHDS e.g.
SELECT * FROM x$ksmhp
WHERE ksmchds = HEXTORAW ('2CA54040');

The
Buffer
Cache

Buffer Headers
 Each buffer has a buffer header
 Buffer headers are stored in same granule as buffers
 Buffer headers include
 Replacement list
 Hash list
 Pointer to buffer
 In RAC only pointer to Lock Element
Buffer
Headers
Granule
Buffers
STOP

X$BH
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
HLADDR RAW(4)
BLSIZ NUMBER
NXT_HASH RAW(4)
PRV_HASH RAW(4)
NXT_REPL RAW(4)
PRV_REPL RAW(4)
FLAG NUMBER
RFLAG NUMBER
SFLAG NUMBER
LRU_FLAG NUMBER
TS# NUMBER
FILE# NUMBER
DBARFIL NUMBER
DBABLK NUMBER
CLASS NUMBER
STATE NUMBER
MODE_HELD NUMBER
CHANGES NUMBER
CSTATE NUMBER
LE_ADDR RAW(4)
DIRTY_QUEUE NUMBER
SET_DS RAW(4)
OBJ NUMBER
BA RAW(4)
CR_SCN_BAS NUMBER
CR_SCN_WRP NUMBER
CR_XID_USN NUMBER
CR_XID_SLT NUMBER
CR_XID_SQN NUMBER
CR_UBA_FIL NUMBER
CR_UBA_BLK NUMBER
CR_UBA_SEQ NUMBER
CR_UBA_REC NUMBER
CR_SFL NUMBER
CR_CLS_BAS NUMBER
CR_CLS_WRP NUMBER
LRBA_SEQ NUMBER
LRBA_BNO NUMBER
HSCN_BAS NUMBER
HSCN_WRP NUMBER
HSUB_SCN NUMBER
US_NXT RAW(4)
US_PRV RAW(4)
WA_NXT RAW(4)
WA_PRV RAW(4)
TCH NUMBER
TIM NUMBER

Head of
Cold End
Head of
Hot End
Single-Block Reads
92
0
34
3
72
4
52
1
71
2
66
0
49
0
42
1
45
2
52
1
71
2
66
0
42
1
11
1
52
1
71
2
11
1
42
1
42
2
71
0
92
0
34
3
72
4
45
2
11
1
52
1
42
2
33
1
45
2
11
1
42
2
33
1
34
4
92
0
34
4
72
4
45
2
11
1
42
0
33
1
71
0
87
1
87
1
72
4
33
1
45
2
Read Block 42
Get first available buffer
from cold end
Update buffer contentsInsert buffer at head of cold
end
Read Block 11
from cold end
end
Read Block 42
Update touch count
for block 42
Read Block 33
Move block 71 to head
of hot end
Set touch count
on block 71 to zero
from cold end
end
Read Block 34
Update touch count
for block 34
Read Block 87
Move block 42 to head
of hot end
Set touch count
on block 42 to zero
from cold end
end
STOP
Block
Number
Touch
Count

Multi-Block Reads
Head of
Cold End
Head of
Hot End
Read Block 1
Get first four available
buffers from cold end
Read next four blocks into
buffers
1 2 3 4
Insert buffers at head of
cold end
12 13 2 14 3 2 1
Move block 1 to cold end
121
Read Block 2
21 321 3 4
Read Block 3
Read Block 4
Read Block 5
Get next four available
buffers from cold end
Read next four blocks into
buffers
Insert buffers at head of
cold end
4 3 2 15
5 56
76
7 6 5
8
78 5 56 5 65 6 75 6 7 8
Read Block 6
Read Block 7
Read Block 8
STOP
DB_FILE_MULTIBLOCK_READ_COUNT = 4

Global
Cache
Services

Read with No Transfer
Instance 1
Instance 2
Instance 4
1318
Request
shared
resource
Instance 3
Resource
Master
Instance 2 requests
current read on
block
Request
granted
SN
Read
request
Block
returned
1318
1
2
3
4
STOP

Read to Write Transfer
Instance 1
Instance 2
Instance 4
1318
Request
exclusive
resource
Instance 3
Resource
Master
Instance 1 requests
exclusive read on
block
Transfer
block to
Instance 1 for
exclusive
access
SN
Block and
resource
status
Resource
status
1318
1
2
3
4
N
N
X
1320
STOP

Write to Write Transfer
Instance 1
Instance 2
Instance 4
1318
Request
block in
exclusive
mode
Instance 3
Resource
Master
Instance 4 requests
exclusive read on
block
Transfer
block to
Instance 4
in exclusive
mode
SN
Block and resource status
Resource
status
1318
12
3
4
N NX
1320
N
N
X
1320 1323
STOP
Note that Instance 1 will
create a past image (PI) of
the dirty block

Past Images
 When an instance passes a dirty block to another instance it
 Flushes redo buffer to redo log
 Retains past image (PI) of block in buffer cache
 PI is retained until another instance writes block to disk
 Used to reduce recovery times
 Recorded in V$BH.STATUS as PI
 Based on X$BH.STATE (value 8 in Oracle 10.2)

Past Images
13281329
UPDATE t1
SET c1 = 1324;
COMMIT;
UPDATE t1
SET c1 = 1329;
COMMIT;
1323
Instance 1
13231324132513261327
Buffer Cache
13241323
13251324
13261325
13271326
1328
13281327
Redo Log 1
Instance 2
Buffer Cache
13291328
UPDATE t1
SET c1 = 1325;
COMMIT;
UPDATE t1
SET c1 = 1326;
COMMIT;
UPDATE t1
SET c1 = 1327;
COMMIT;
UPDATE t1
SET c1 = 1328;
COMMIT; 1328
1323
Redo Log 2
1323
132813291329
1329
1329
Assume table t1 contains a
single row in block 42
Instance 1 updates column to
1324
Block 42 is read from disk
Undo/Redo written to
Redo Log 1
Block 42 is updated in buffer
cache
1325
Redo Log 1
cache
1326
Redo Log 1
cache
1327
Redo Log 1
cache
1328
Redo Log 1
cache
1329
GCS transfers block from
Instance 1 to Instance 2
Instance 1 makes block 42
a Past Image block
Undo/redo written to
Redo Log 2
cache
Instance 2 Crashes
Contents of buffer cache are lost
DBWR has not written changes
to block 42 back to disk yet
Instance 1 must perform
recovery for Instance 2
Block 42 needs recovery
Instance 1 uses Past Image
Undo/redo is applied from
Redo Log 2
Block 42 is subsequently written
back to disk by DBWR
STOP

Write to Read Transfer
Instance 1
Instance 2
Instance 4
1318
Request block in
shared mode
Instance 3
Resource
Master
Instance 2 requests
current read on
block
SN
Block and resource status
Resource
status
1318
1
3
4
N NX
1320
N
N
X
1320 1323
Transfer
block to
Instance 1
in shared
mode
2
S
S
STOP
Note that in recent versions
_fairness_threshold is used
to avoid unnecessary lock
conversions

Fairness Threshold
 Intended to prevent unnecessary lock downgrades when
other instances only require read-only copies
 For write to read transfers
 Writing instance retains X lock
 Reading instance retains null lock
 If _fairness_threshold reached then
 Writing instance downgrades X lock to S lock
 Reading instance receives S lock
 _fairness_threshold default value is 4

Fairness Threshold
Assume instance 1 holds
exclusive lock on block
Instance 2
Instance 2 requests consistent
read
Instance 1 sets counter to 1
Instance 1 sends block to
Instance 2
13231323
Instance 1
X
Instance 2 receives block with
Null lock
13231323
01234 N
read
Instance 2
Null lock
1323
read
instance 2
Null lock
read
Instance 1 downgrades lock from
X to S
S
Instance 2
Shared lock
S
_fairness_threshold = 4
STOP

Lock Elements
 Contain embedded GCS Client structures (KJBL)
Lock
Element
GCS
Client
Buffer
Header
Lock
Element
GCS
Client
Buffer
Header
Buffer
Header
Lock
Element
GCS
Client

V$LOCK_ELEMENT
 Based on X$LE
LOCK_ELEMENT_ADDR RAW(4)
INDX NUMBER
CLASS NUMBER
LOCK_ELEMENT_NAME NUMBER
MODE_HELD NUMBER
BLOCK_COUNT NUMBER
RELEASING NUMBER
ACQUIRING NUMBER
INVALID NUMBER
FLAGS NUMBER

X$LE
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
LE_ADDR RAW(4)
NAME NUMBER
LE_CLASS NUMBER
LE_RLS NUMBER
LE_ACQ NUMBER
LE_FLAGS NUMBER
LE_MODE NUMBER
LE_WRITE NUMBER
LE_LOCAL NUMBER
LE_RECOVERY NUMBER
LE_BLKS NUMBER
LE_TIME NUMBER
LE_KJBL RAW(4)
Buffer
Header
Lock
Element
GCS
Client
STOP

Global Cache Services
KJBRKJBR
KJBL
BH BH
LE
KJBL
LE
KJBL
GCS
Client
GCS
Shadow

GCS Parameters
 GCS Resources
 Number of GCS resource structures determined by
 _gcs_resources parameter
 Stored in segmented array
 Externalized in X$KJBR
 Number of free GCS resource structures in X$KJBRFX
 GCS Enqueues (Shadows/Clients)
 Number of GCS enqueue structures determined by
 _gcs_shadow_locks parameter
 Externalized in X$KJBL
 Number of free GCS enqueue structures in X$KJBLFX

X$KJBR
 Externalizes GCS Resources
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KJBRRESP RAW(4)
KJBRGRANT VARCHAR2(9)
KJBRNCVL VARCHAR2(9)
KJBRROLE NUMBER
KJBRNAME VARCHAR2(30)
KJBRMASTER NUMBER
KJBRGRANTQ RAW(4)
KJBRCVTQ RAW(4)
KJBRWRITER RAW(4)

X$KJBL
 Externalizes GCS Enqueues
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KJBLLOCKP RAW(4)
KJBLGRANT VARCHAR2(9)
KJBLREQUEST VARCHAR2(9)
KJBLROLE NUMBER
KJBLRESP RAW(4)
KJBLNAME VARCHAR2(30)
KJBLNAME2 VARCHAR2(30)
KJBLQUEUE NUMBER
KJBLLOCKST VARCHAR2(64)
KJBLWRITING NUMBER
KJBLREQWRITE NUMBER
KJBLMASTER NUMBER
KJBLBLOCKED NUMBER
KJBLBLOCKER NUMBER

Global Cache Dumps
 To dump the contents of the global cache use:
ALTER SESSION SET EVENTS
'IMMEDIATE TRACE NAME GC_ELEMENTS LEVEL 1';
GLOBAL CACHE ELEMENT DUMP (address: 0x21fecd18):
id1: 0x3591 id2: 0x10000 obj: 181 block: (1/13713)
lock: SL rls: 0x0000 acq: 0x0000 latch: 0
flags: 0x41 fair: 0 recovery: 0 fpin: 'kdswh05: kdsgrp'
bscn: 0x0.18a9c bctx: (nil) write: 0 scan: 0x0 xflg: 0 xid: 0x0.0.0
GCS CLIENT 0x21fecd60,1 sq[(nil),(nil)] resp[(nil),0x3591.10000] pkey 181
grant 1 cvt 0 mdrole 0x21 st 0x20 GRANTQ rl LOCAL
master 1 owner 0 sid 0 remote[(nil),0] hist 0x7c
history 0x3c.0x1.0x0.0x0.0x0.0x0. cflag 0x0 sender 2 flags 0x0 replay# 0
disk: 0x0000.00000000 write request: 0x0000.00000000
pi scn: 0x0000.00000000
msgseq 0x1 updseq 0x0 reqids[1,0,0] infop 0x0
pkey 181
hv 107 [stat 0x0, 1->1, wm 32767, RMno 0, reminc 6, dom 0]
kjga st 0x4, step 0.0.0, cinc 8, rmno 10, flags 0x0
lb 0, hb 0, myb 178, drmb 178, apifrz 0

Global Cache Dumps
 Continued
GLOBAL CACHE ELEMENT DUMP (address: 0x237f4358):
id1: 0x6a39 id2: 0x10000 obj: 74 block: (1/27193)
lock: SL rls: 0x0000 acq: 0x0000 latch: 0
flags: 0x41 fair: 0 recovery: 0 fpin: 'kdswh05: kdsgrp'
bscn: 0x0.26992 bctx: (nil) write: 0 scan: 0x0 xflg: 0 xid: 0x0.0.0
GCS SHADOW 0x237f43a0,1 sq[0x2ee64e8c,0x2eff3858] resp[0x2ee64e74,0x6a39.10000] pkey 74
master 0 owner 0 sid 0 remote[(nil),0] hist 0x12a5
.....
GCS RESOURCE 0x2ee64e74 hashq [0x2ee61894,0x2ff57390] name[0x6a39.10000] pkey 74
grant 0x2eff3858 cvt (nil) send (nil),0 write (nil),0@65535
flag 0x0 mdrole 0x1 mode 1 scan 0 role LOCAL
.....
GCS SHADOW 0x2eff3858,1 sq[0x237f43a0,0x2ee64e8c] resp[0x2ee64e74,0x6a39.10000] pkey 74
master 0 owner 1 sid 0 remote[0x23fea160,1] hist 0x65f
.....
GCS SHADOW 0x237f43a0,1 sq[0x2ee64e8c,0x2eff3858] resp[0x2ee64e74,0x6a39.10000] pkey 74
master 0 owner 0 sid 0 remote[(nil),0] hist 0x12a5
.....

Block Mastering
 Each block is mastered on one instance
 Block DBA is reported by X$KJBR.KJBRNAME
 Names for have the format:
 [<block_number>][<file_number>],[BL]
 Ordering by X$KJBR.KJBRNAME is difficult because
the resource names do not collate e.g.
 [0x900][0x70000],[BL]
 [0x90][0x70000],[BL]
 Current master reported by X$KJBR.KJBRMASTER

Block Mastering
 In Oracle 10.2 block mastering is determined by
 _lm_contiguous_res_count
 Specifies number of contiguous blocks that will hash to the
same HV bucket
 Defaults to 128
 For example
Start End
0x080 0x0FF
0x180 0x1FF
0x280 0x2FF
0x380 0x3FF
0x480 0x4FF
0x580 0x5FF
etc etc
Start End
0x000 0x07F
0x100 0x17F
0x200 0x27F
0x300 0x37F
0x400 0x47F
0x500 0x57F
etc etc
Instance 0 Instance 1

Block Mastering
 In Oracle 9.2 (and probably 10.1) block mastering determined
by hash function
 Algorithm applied to groups of 1289 contiguous blocks
 In two node cluster
 instance 0 has 645 blocks
 In three node cluster
 Beware of small hot tables and indexes....

Dynamic Remastering
 In Oracle 9.2
 documentation describes dynamic remastering
 not implemented in code
 In Oracle 10.1
 work at data file level
 very high threshold so difficult to test
 does occur on some customer sites
 may cause LMON process to crash in 10.1.0.4
 bug 3659289 - patch available
 fixed in 10.1.0.5/10.2.0.1
 In Oracle 10.2
 works at object level
 thresholds are relatively low

Dynamic Remastering
 Example
SELECT data_object_id FROM dba_objects
WHERE owner = 'US01'AND object_name = 'T1';
OBJECT_ID
---------
52084
ORADEBUG LKDEBUG -m pkey 52084
 To remaster object at current instance use:
 All blocks now mastered by the current instance
 To redistribute masters to all available instances use:
ORADEBUG LKDEBUG -m dpkey 52084
 Blocks mastered by both (all) instances again

V$GCSPFMASTER_INFO
 Object re mastering is recorded in V$GCSPFMASTER_INFO
FILE_ID NUMBER
OBJECT_ID NUMBER
CURRENT_MASTER NUMBER
PREVIOUS_MASTER NUMBER
REMASTER_CNT NUMBER

Dynamic Remastering
 Object remastering recorded in V$GCSPFMASTER_INFO
 Instances are internally numbered 0, 1 etc
 Initially contains no rows
 After remastering object 52084 to instance 0
SELECT object_id, current_master, previous_master
FROM v$gcspfmaster_info;
 After remastering object 52084 to instance 1
Object ID Current Master Previous Master
52084 0 32767
Object ID Current Master Previous Master
52084 1 0

Dynamic Remastering
 Information about Dynamic Remastering operations is also
recorded in the following fixed views
 X$KJDRMREQ
 Dynamic Remastering Requests
 X$KJDRMAFNSTATS
 File Remastering Statistics
 X$KJDRMHVSTATS
 Hash Value Statistics

The
Library
Cache

Library Cache Object - Parent
16 x 1 word
pointers
KGLHD
Parent
Object
KGLNA
SELECT SUM (c2) FROM t1
WHERE c3 = 42 AND c4 < 2004
Parent
Name
Child
Handle
KGLHD
Child 1
Child 2
Heap 0
KGLOB
X$KGLOB
Parent
Handle
KGLHD
STOP

Library Cache Object - Child
KGLHD
Child
Handle
Child
Object
SELECT
Statement
Heap 6
KGLOB
Subheap
Header
Subheap
Header
Heap 0
Subquery
Header
Statistics,
Optimizer
Environment,
BindVariables
X$KGLOB
STOP

Library Cache
 In general
 Locks are required for parsing
 Externalized in X$KGLLK
 Pins are required for execution
 Externalized in X$KGLPN
 Each KGLHD structure has a set of double linked lists
including;
 Locks
 Pins

X$KGLPN
X$KGLLK
Library Cache Object - Locks & Pins
Child
Handle
Child
Object
KGLOB
X$KGLOB
STOP
LockLock
Pin
Lock
Pin Pin
KGLHD

Namespaces
 In Oracle 10.2 there are 64 library cache namespaces
 Externalized by KGLHDNSP in X$KGLOB
CRSR LOB REIP RMGR JVSD RELS MVOBINX NSCPD
TABL DIR CPOB XDBS STFG RELD STBO JSLV
BODY QUEU EVNT PPLN TRANS IFSD HTSO MODL
TRGR OBJG SUMM PCLS RELC XDBC JSGA Unused
INDX PROP DIMM SUBS RULE USAG JSET Unused
CLST JVSC CTS LOCS STRM MVOBTBL TABLE Unused
KGLT JVRE OUTL RMOB REVC JSQI CLST Unused
PIPE ROBJ RULS RSMD STAP CDC INDX Unused

Namespaces
 Library cache statistics can be dumped using:
'IMMEDIATE TRACE NAME LIBRARY_CACHE LEVEL 1';
 For example:
LIBRARY CACHE STATISTICS:
namespace gets hit ratio pins hit ratio reloads invalids
-------------- --------- --------- --------- --------- ---------- ----------
CRSR 2403 0.086 33698 0.933 435 0
TABL 4368 0.578 10032 0.657 961 0
BODY 127 0.717 211 0.801 4 0
TRGR 4 0.000 45 0.911 0 0
INDX 81 0.272 83 0.036 21 0
CLST 101 0.921 264 0.958 3 0
KGLT 0 0.000 0 0.000 0 0
PIPE 0 0.000 0 0.000 0 0
LOB 0 0.000 0 0.000 0 0
DIR 0 0.000 0 0.000 0 0
QUEU 156 0.904 5886 0.997 0 0
....

V$LIBRARYCACHE
 Subset of rows from X$KGLST
 Contains 11 rows in Oracle 10.2
NAMESPACE VARCHAR2(15)
GETS NUMBER
GETHITS NUMBER
GETHITRATIO NUMBER
PINS NUMBER
PINHITS NUMBER
PINHITRATIO NUMBER
RELOADS NUMBER
INVALIDATIONS NUMBER
DLM_LOCK_REQUESTS NUMBER
DLM_PIN_REQUESTS NUMBER
DLM_PIN_RELEASES NUMBER
DLM_INVALIDATION_REQUESTS NUMBER
DLM_INVALIDATIONS NUMBER
RAC
Specific
Statistics

SELECT inst_id,
DECODE (indx,
0,'SQL AREA',
1,'TABLE/PROCEDURE',
2,'BODY',
3,'TRIGGER',
4,'INDEX',
5,'CLUSTER',
6,'OBJECT',
7,'PIPE',
13,'JAVA SOURCE',
14,'JAVA RESOURCE',
32,'JAVA DATA','
?'
),
kglstget,kglstght, DECODE (kglstget,0,1,kglstght/kglstget),
kglstpin,kglstpht, DECODE (kglstpin,0,1,kglstpht/kglstpin),
kglstrld,kglstinv, kglstlrq,kglstprq,kglstprl,kglstirq,kglstmiv
FROM x$kglst
WHERE indx<8 OR indx=13 OR indx=14 OR indx=32
V$LIBRARYCACHE
 Based on X$KGLST
Names are generated
in dynamic
performance view
Only selected rows
from X$KGLST

X$KGLST
 Contains one row for each namespace (59 rows in 10.2)
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KGLSTCMS NUMBER
KGLSTCHT NUMBER
KGLSTGET NUMBER
KGLSTGHT NUMBER
KGLSTPIN NUMBER
KGLSTPHT NUMBER
KGLSTRLD NUMBER
KGLSTINV NUMBER
KGLSTLRQ NUMBER
KGLSTPRQ NUMBER
KGLSTPRL NUMBER
KGLSTIRQ NUMBER
KGLSTMIV NUMBER
RAC
Specific
Statistics

Global
Enqueue
Services

V$LOCK_TYPE
 Introduced in Oracle 10.1
 Lists all lock types
 Wildcards for
 Library Cache Locks and Pins
 Row Cache Locks
TYPE VARCHAR2(64)
NAME VARCHAR2(64)
ID1_TAG VARCHAR2(64)
ID2_TAG VARCHAR2(64)
IS_USER VARCHAR2(3)
DESCRIPTION VARCHAR2(4000)

Library Cache Objects
 Library Cache Objects can be dumped using:
'IMMEDIATE TRACE NAME LIBRARY_CACHE LEVEL 4';
BUCKET 127469:
LIBRARY OBJECT HANDLE: handle=2bb8dfbc mutex=0x2bb8e070(0)
name=US01.T1
hash=b2f454b86387761e02fc7e686e37f1ed timestamp=01-14-2006 22:04:06
namespace=TABL flags=KGHP/TIM/MED/[40000000]
kkkk-dddd-llll=0000-0701-0701 lock=0 pin=0 latch#=1 hpc=0002 hlc=0002
lwt=0x2bb8e018[0x2bb8e018,0x2bb8e018] ltm=0x2bb8e020[0x2bb8e020,0x2bb8e020]
pwt=0x2bb8dffc[0x2bb8dffc,0x2bb8dffc] ptm=0x2bb8e004[0x2bb8e004,0x2bb8e004]
ref=0x2bb8e038[0x2bb8e038,0x2bb8e038] lnd=0x2bb8e044[0x2bb7a7ac,0x2bb8e410]
LOCK INSTANCE LOCK: id=LBb2f454b86387761e
PIN INSTANCE LOCK: id=NBb2f454b86387761e mode=S release=F flags=[00
INVALIDATION INSTANCE LOCK: id=IV0000c9890e170507 mode=S
LIBRARY OBJECT: object=2caede30
type=TABL flags=EXS/LOC[0005] pflags=[0000] status=VALD load=0
BUCKET 127469 total object count=1
 For example:

Library Cache Instance Locks
 Instance Locks created for
 Library Cache Locks
 Library Cache Pins
 Lock name based on object hash value (KGLNAHSH)
 For example:
BUCKET 127469:
LIBRARY OBJECT HANDLE: handle=2bb8dfbc mutex=0x2bb8e070(0)
name=US01.T1
hash=b2f454b86387761e02fc7e686e37f1ed timestamp=01-14-2006 22:04:06
namespace=TABL flags=KGHP/TIM/MED/[40000000]
kkkk-dddd-llll=0000-0701-0701 lock=0 pin=0 latch#=1 hpc=0002 hlc=0002
lwt=0x2bb8e018[0x2bb8e018,0x2bb8e018] ltm=0x2bb8e020[0x2bb8e020,0x2bb8e020]
pwt=0x2bb8dffc[0x2bb8dffc,0x2bb8dffc] ptm=0x2bb8e004[0x2bb8e004,0x2bb8e004]
ref=0x2bb8e038[0x2bb8e038,0x2bb8e038] lnd=0x2bb8e044[0x2bb7a7ac,0x2bb8e410]
LOCK INSTANCE LOCK: id=LBb2f454b86387761e
PIN INSTANCE LOCK: id=NBb2f454b86387761e mode=S release=F flags=[00
INVALIDATION INSTANCE LOCK: id=IV0000c9890e170507 mode=S
LIBRARY OBJECT: object=2caede30
type=TABL flags=EXS/LOC[0005] pflags=[0000] status=VALD load=0

Library Cache Instance Locks
 For example in library cache dump
 Library cache pin instance lock is
 id=NBb2f454b86387761e
 In X$KJIRFT this KJIRFTRN column
 [0xb2f454b8][0x6387761e],[NB]

Namespaces->Instance Locks
 Slide 1 of 3
Namespace Lock Pin
JVSC LN NN
JVRE LO NO
ROBJ LP NP
REIP LQ NQ
CPOB LR NR
EVNT LS NS
SUMM LT NT
DIMM LU NU
CTS LV NV
OUTL LW NW
RULS LX NX
RMGR LY NY
XDBS LZ NZ
Namespace Lock Pin
CRSR LA NA
TABL LB NB
BODY LC NC
TRGR LD ND
INDX LE NE
CLST LF NF
KGLT LG NG
PIPE LH NH
LOB LI NI
DIR LJ NJ
QUEU LK NK
OBJG LL NL
PROP LM NM

 Slide 2 of 3
Namespace Lock Pin
STAP EN GN
RELS EO GO
RELD EP GP
IFSD EQ GQ
XDBC ER GR
USAG ES GS
MVOBTBL ET GT
JSQI EU GU
CDC EV GV
MVOBINX EW GW
STBO EX GX
HTSO EY GY
JSGA EZ GZ
Namespace Lock Pin
PPLN EA GA
PCLS EB GB
SUBS EC GC
LOCS ED GD
RMOB EE GE
RSMD EF GF
JVSD EG GG
STFG EH GH
TRANS EI GI
RELC EJ GJ
RULE EK GK
STRM EL GL
REVC EM GM

 Slide 3 of 3
Namespace Lock Pin
JSET VA YA
TABLE VB YB
CLST VC YC
INDX VD YD
NSCPD VE YE
JSLV VF YF
MODL VG YG
Unused VH YH
Unused VI YI
Unused VJ YJ
Unused VK YK
Unused VL YL
Unused VM YM

V$ROWCACHE
CACHE# NUMBER
TYPE VARCHAR2(11)
SUBORDINATE# NUMBER
PARAMETER VARCHAR2(32)
COUNT NUMBER
USAGE NUMBER
FIXED NUMBER
GETS NUMBER
GETMISSES NUMBER
SCANS NUMBER
SCANMISSES NUMBER
SCANCOMPLETES NUMBER
MODIFICATIONS NUMBER
FLUSHES NUMBER
DLM_REQUESTS NUMBER
DLM_CONFLICTS NUMBER
DLM_RELEASES NUMBER
RAC
Specific
Statistics

V$ROWCACHE
 Based on X$KQRST
 Contains 42 rows in Oracle 10.2
 34 Parent Cache
 8 Subordinate Caches

Row Caches->Instance Locks
 Slide 1 of 2
Cache# Namespace Lock
0 dc_tablespaces QA
1 dc_free_extents QB
2 dc_segments QC
3 dc_rollback_segments QD
4 dc_used_extents QE
5 dc_tablespace_quotas QF
6 dc_files QG
7 dc_users QH
8 dc_objects QI
9 dc_qmc_cache_entries QJ
10 dc_usernames QK
11 dc_object_ids QL
12 dc_constraints QM
13 dc_sequences QN
14 dc_profiles QO
15 dc_database_links QP
16 dc_histogram_defs QQ
17 dc_global_oids QR
18 dc_outlines QS
19 dc_table_scns QT
20 rule_info QU
21 rule_or_piece QV
22 dc_awr_control QW
23 dc_qmc_ldap_cache... QX
24 outstanding_alerts QY
25 dc_hintsets QZ

Row Caches->Instance Locks
 Slide 2 of 2
26 global_database_name ??
27 qmtmrcin_cache_entries ??
28 qmtmrctn_cache_entries ??
29 qmtmrcip_cache_entries ??
30 qmtmrctp_cache_entries ??
31 qmtmrciq_cache_entries ??
32 qmtmrctq_cache_entries ??
33 kqlsubheap_object ??
 Cache# = KQRSTCID

Row Caches
 Row cache statistics can be dumped using:
'IMMEDIATE TRACE NAME ROW_CACHE LEVEL 1';
 For example:
ROW CACHE STATISTICS:
cache size gets misses hit ratio DLM req
-------------------------- ------- ------- ------ --------- -------
dc_tablespaces 496 8909 7 0.999 7
dc_free_extents 388 0 0 0.000 0
dc_segments 444 4191 569 0.880 709
dc_rollback_segments 452 4210 31 0.993 74
dc_used_extents 400 0 0 0.000 0
dc_tablespace_quotas 396 0 0 0.000 0
dc_files 412 0 6 0.000 6
dc_users 520 9042 23 0.997 23
dc_users 260 0 0 0.000 0
dc_user_grants 108 24 17 0.585 0
dc_app_role 100 0 0 0.000 0
....

BUCKET 48205:
row cache parent object: address=0x2bb8dcd8 cid=8(dc_objects)
hash=313bbc4c typ=9 transaction=(nil) flags=00000002
own=0x2bb8dd44[0x2bb8dd44,0x2bb8dd44]
wat=0x2bb8dd4c[0x2bb8dd4c,0x2bb8dd4c] mode=S
status=VALID/-/-/-/-/-/-/-/-
request=N release=FALSE flags=0
instance lock id=QI f611ffad e31d1de3
set=0, complete=FALSE
data=
00000037 31540002 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000001 00000000 00000000 00000000 00000000 00000000 00000000
......
00000000 00000000 00000000 0000c989 00000001 0000c989 016a7802 0705170e
0e016a78 78070517 170e016a 00010705 00000000 00000000 00000000 00000000
00000000 00000006
Row Caches
 Row cache statistics can be dumped using:
'IMMEDIATE TRACE NAME ROW_CACHE LEVEL 8';
 For example:
T1
Instance Lock
QI F611FFAD E31D1DE3
Cache ID 8
dc_objects

GES
Resource
Global Enqueue Services
KJIRFT
KJILKFT
GES
EnqueueKJILKFT KJILKFT
KJILKFTKJILKFT
KJILKFT
Holders Converters Waiters

Resource Names
 Contain
 1 x two byte name
 2 x 32 bit integer tag fields
 Used with
 Resources
 Enqueues
 Locks
 Global Enqueue Services
 Global Cache Services
 Block are resources with resource name BL

Resource Names
 Externalized inconsistently throughout Oracle in
 V$/GV$ dynamic performance views
 X$ fixed tables
 Dumps and trace files
 Stored consistently in internal C structures including
 KJBR
 KJIRFT
 Other structures reference the resource names in these
structures including
 KJBL
 KJILFKT

GES Parameters
 GES Resources
 Number of GES resource structures probably determined
by
 _lm_ress parameter
 Stored in heap
 Externalized in X$KJIRFT
 GES Enqueues
 Number of GES enqueue structures probably determined
by
 _lm_locks parameter
 Externalized in X$KJILKFT

X$KJIRFT
 Externals global enqueue resources
 Does NOT include global cache resources
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KJIRFTRP RAW(4)
KJIRFTRN VARCHAR2(30)
KJIRFTCQ NUMBER
KJIRFTGQ NUMBER
KJIRFTPR NUMBER
KJIRFTRDN VARCHAR2(25)
KJIRFTMN NUMBER
KJIRFTNCL VARCHAR2(9)
KJIRFTVS VARCHAR2(32)
KJIRFTVB VARCHAR2(64)

X$KJILKFT
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KJILKFTLKP RAW(4)
KJILKFTGL VARCHAR2(9)
KJILKFTRL VARCHAR2(9)
KJILKFTRP RAW(4)
KJILKFTRN1 VARCHAR2(30)
KJILKFTRN2 VARCHAR2(30)
KJILKFTPID NUMBER
KJILKFTXID0 NUMBER
KJILKFTXID1 NUMBER
KJILKFTGID NUMBER
KJILKFTOODD NUMBER
KJILKFTOOPT NUMBER
KJILKFTOOPO NUMBER
KJILKFTOONXID NUMBER
KJILKFTCOGV NUMBER
KJILKFTCOPV NUMBER
KJILKFTCONV NUMBER
KJILKFTCODV NUMBER
KJILKFTCONQ NUMBER
KJILKFTCOEP NUMBER
KJILKFTCONDDW NUMBER
KJILKFTCONDDB NUMBER
KJILKFTWQ NUMBER
KJILKFTLS VARCHAR2(64)
KJILKFTASTE0 NUMBER
KJILKFTON NUMBER
KJILKFTBLKED NUMBER
KJILKFTBLKER NUMBER

V$GES_RESOURCE
 Contains rows from both KJIRFT and KJBR
 Synonym for V$DLM_RESS
RESP RAW(4)
RESOURCE_NAME VARCHAR2(30)
ON_CONVERT_Q NUMBER
ON_GRANT_Q NUMBER
PERSISTENT_RES NUMBER
MASTER_NODE NUMBER
NEXT_CVT_LEVEL VARCHAR2(9)
VALUE_BLK_STATE VARCHAR2(32)
VALUE_BLK VARCHAR2(64)

V$GES_RESOURCE
 Contains rows from both KJIRFT and KJBR
 Synonym for V$DLM_RESS
SELECT
inst_id, kjirftrp, kjirftrn, kjirftcq, kjirftgq, kjirftpr, kjirftmn, kjirftncl,
kjirftvs, kjirftvb
FROM x$kjirft
UNION ALL
SELECT
inst_id, kjbrresp, kjbrname, DECODE (kjbrcvtq, '00', 0, 1),
DECODE (kjbrgrantq, '00', 0, 1), 1, kjbrmaster, kjbrncvl,
'KJUSERVS_NOVALUE', '0x0'
FROM x$kjbr

V$GES_ENQUEUE
 Contains rows from both KJILKFT and KJBL
HANDLE RAW(4)
GRANT_LEVEL VARCHAR2(9)
REQUEST_LEVEL VARCHAR2(9)
RESOURCE_NAME1 VARCHAR2(30)
RESOURCE_NAME2 VARCHAR2(30)
PID NUMBER
TRANSACTION_ID0 NUMBER
TRANSACTION_ID1 NUMBER
GROUP_ID NUMBER
OPEN_OPT_DEADLOCK NUMBER
OPEN_OPT_PERSISTENT NUMBER
OPEN_OPT_PROCESS_OWNED NUMBER
OPEN_OPT_NO_XID NUMBER
CONVERT_OPT_GETVALUE NUMBER
CONVERT_OPT_PUTVALUE NUMBER
CONVERT_OPT_NOVALUE NUMBER
CONVERT_OPT_DUBVALUE NUMBER
CONVERT_OPT_NOQUEUE NUMBER
CONVERT_OPT_EXPRESS NUMBER
CONVERT_OPT_NODEADLOCKWAIT NUMBER
CONVERT_OPT_NODEADLOCKBLOCK NUMBER
WHICH_QUEUE NUMBER
STATE VARCHAR2(64)
AST_EVENT0 NUMBER
OWNER_NODE NUMBER
BLOCKED NUMBER
BLOCKER NUMBER

V$GES_ENQUEUE
 Contains rows from both KJILKFT and KJBL
SELECT
inst_id, kjilkftlkp, kjilkftgl, kjilkftrl, kjilkftrn1, kjilkftrn2, kjilkftpid,
kjilkftxid0, kjilkftxid1, kjilkftgid, kjilkftoodd, kjilkftoopt, kjilkftoopo,
kjilkftoonxid, kjilkftcogv, kjilkftcopv, kjilkftconv, kjilkftcodv, kjilkftconq,
kjilkftcoep, kjilkftconddw, kjilkftconddb, kjilkftwq, kjilkftls, kjilkftaste0,
kjilkfton, kjilkftblked, kjilkftblker
FROM x$kjilkft
UNION ALL
SELECT inst_id,
kjbllockp, kjblgrant, kjblrequest, kjblname, kjblname2, 0, 0, 0, 0, 0, 1, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, kjblqueue, kjbllockst, 0, kjblowner, kjblblocked,
kjblblocker
FROM x$kjbl

Thank you for your interest
For more information and to provide feedback
please contact me
My e-mail address is:
info@juliandyke.com
My website address is:
www.juliandyke.com

RAC MEMORY STRUCTURES

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