PMON
Fork
R
u
User
Session
Data
- LMON
- LCKn,
- LMSn
- LMDn
- ORACM
- GSD
- DIAG
Real Application
Clusters *
- RBAL
- ARBn
- ASMB
Automatic
Storage
Management *
- sysaux01.dbf
Data
Dictionary
Data files
- system01.dbf
nk *
block
size
- QMNC
- Qnnn
- EMNn
Advanced
Queuing *
Temporary
Tablespace Group
Data Files
Cursor
State
UGA
Oracle supports Bigfile
Tablespaces and nonstandard block sizes
Stack
Space
Program Global Area (PGA)
System
Parameters
keep
MRU
C
Default
Pool
process
D
C
Midpoint
insertion
DBWn
D
C
D
CKPT
Server
Parameter
file
spfileSID.ora
Parameter
file
initSID.ora
Misc
file(s)
alert_SID.ora
trace
Data
Guard
Broker
Config
Multiplexed Group 2
Data
CJQn *
ARCn *
Streams
Pool *
Java
Pool
Fixed
Area
(Static
Overhea
d)
SGA_TARGET (Dynamic) *
Disk
Cross-platform
transportable
tablespaces
To another
Instance
Tape
MML
Data Guard
Managed Recovery
MRPn *
Parallel Query
Pnnn *
Intelligent Agent
DBSNMP *
Mich Talebzadeh
mich@peridale.co.uk
Version 2, Jan 2006.
Oracle managed
backups with
RMAN
RMAN
Multiplexed
Archived Redo
Logs
Archiver process copies an
online redo log file to
another location when the
redo log file is filled up or
there is a log switch
Recovery
catalog *
Request
Queue
Response
Queue
UGA
I/O Buffer
Area
UGA *
Sort
Extent
Pool
Job Queue Processes.
Selects jobs that need to
be run, .
Replication and Queuing
NOT PERSISTENT
Large Pool
Flushes redo log buffer to
online redo log file every 3
seconds, in commits, and
checkpoints or when the
redo log buffer is 1MB or
more than 1/3 full.
LGWR
Redo Log
Buffer
Online Redo Logs
Multiplexed Group 1
Data
- Shutdown
- Regularly initiates a
checkpoint. Uses DBWR
to write all dirty blocks
- Updates data file headers
LRU
RECO
CPUs
The Distributed
Transaction Recovery
Process finds pending
distributed transactions
and resolves them
* indicates optional setup
Password
File
orapwSID
Data
Multiplexed
Control Files
Dirty Buffer threshold
Scan 1/2 LRU list
Full Checkpoints
Timeout 3 seconds
8K *
read
C
Checkpoint Queue
cold area
go
an
sc
e
l
d
tab en
ull LRU
hf
wit ly to
s
ck ate
Blo edi
m
im
blocks with recurring
access
Individual blocks
read from disk go to
the middle
nK *
recycle
D
hot area
MMON *
Captures statistics for SQL
objects which have been
recently modified
aged blocks (non recurring access)
Database Buffer Cache
- RVWR, Flashback
- CTWR, change tracking
Others *
Data Files
MMAN *
Dynamically ajusts the
size of SGA components
System Global Area
Stack
Space
Used in Shared Server
Environment
Snn*/Dnn
Operating System
Oracle background processes are persistent
processes that make up the instance and they
will run until the instance is shutdown. They
are processes, not programs. There is only
one Oracle program on the host, i.e. there is
only one binary, named oracle. It is just
executed many times with different names
Latches
Data Dictionary Cache
f (also known as Row Cache)
- Hash Value
- SQL Source
- Execution plan
Shared SQL Area
Shared Pool
st *
eque
ect R
n
n
o
C
Library Cache
ing
Incom
o
n
io
rs
ve e
e d
im coEnqueues
nt
Server Process
Network Files
- listener.ora
- tnsnames.ora
- sqlnet.ora
SMON
- Crash Recovery
- Clean Temp Segments
- Collates Free Space
CPUs
User’s privileges
- Cleans User & Server
Processes
- Registers service with
listener
Listener
Oracle Net,
tnsnames.ora
™
ard
ed
Dis
c
s
(A
g
ed
)B
loc
k
User Process
SGA_MAX_SIZE (Fixed at start-up)