Oracle Basics and Architecture

DBA Team 1

Oracle Architecture

DBA Team 2

Cost: Enterprise Edition

US$47,500.00 / Processor

DBA Team 3

Agenda

• What is Oracle1. instance2. Database3. Listener

• Cost Base Optimizer

DBA Team 4

Memorize

more

less

Shallow In-depthUnderstanding

The more you understandThe less you need to memorize

DBA Team 5

Startup nomount

• Instance Started

Mount

• Control file opened for this instance

Open

• Database opened for this instance

DBA Team 6

Connected to an idle instance.

sys@CS11GR2> !ps -ef | grep cs11gR2 | grep -v grep

sys@CS11GR2> !ipcs -m

------ Shared Memory Segments --------key shmid owner perms bytes nattch

status

Before startup

DBA Team 7

sys@CS11GR2> startup nomountORACLE instance started.

Total System Global Area 535662592 bytesFixed Size 1337720 bytesVariable Size 322963080 bytesDatabase Buffers 205520896 bytesRedo Buffers 5840896 bytes

instance startup

DBA Team 8

After instance is started

sys@CS11GR2> !ipcs -m

------ Shared Memory Segments --------key shmid owner perms bytes nattch

status0x44c4474c 360449 oracle 660 538968064 16

DBA Team 9

Listener

System Monitor(SMON)

DatabaseWriter(DBW0)

ProcessMonitor(PMON)

Check Point(CKPT)

LogWriter(LGWR)

Archiver(ARC0)

Oracle Background Processes

DataFiles

ControlFiles

Redo Log Files

Data Base

Instance

Server Processes

Client Processes

DatabaseBuffer Cache

Library Cache Redo Log BufferData Dictionary Cache

Shared PoolSystem Global Area

DBA Team 10

After instance is started

sys@CS11GR2> !ps -ef | grep cs11gR2 | grep -v grep

oracle 13134 1 0 13:54 ? 00:00:00 ora_dbw0_cs11gR2oracle 13136 1 0 13:54 ? 00:00:00 ora_lgwr_cs11gR2

...

oracle 13116 1 0 13:54 ? 00:00:00 ora_pmon_cs11gR2 oracle 13140 1 0 13:54 ? 00:00:00 ora_smon_cs11gR2

SQL> !ps -ef | grep cs11gR2 | grep -v grep | wc -l16

DBA Team 11

DataFiles

ControlFiles

Redo Log Files

Data Base

Listener

Server Processes

Client Processes

Instance







Check Point(CKPT)

LogWriter(LGWR)

Archiver(ARC0)


DBA Team 12

Open the Databasesys@CS11GR2> alter database mount;Database altered.

sys@CS11GR2> alter database open;Database altered.

sys@CS11GR2> select * from sid.emp where ename='SMITH'; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO------ ---------- --------- ------ --------- ----- ------ -------- 7369 SMITH CLERK 7902 17-DEC-80 800 20

1 row selected.

DBA Team 13

Listener

Server Processes

Client Processes

DataFiles

ControlFiles

Redo Log Files

Data Base

Instance







Check Point(CKPT)

LogWriter(LGWR)

Archiver(ARC0)


DBA Team 14

Connect from RemoteFailed!

C:\Documents and Settings\chensi4>sqlplus sid/sid@cs11g

SQL*Plus: Release 10.2.0.1.0 - Production on Sun Jul 24 20:29:17 2011

Copyright (c) 1982, 2005, Oracle. All rights reserved.

ERROR:

ORA-12541: TNS:no listener

DBA Team 15

Startup the Listeneroracle@cargosmart:~/scripts$ lsnrctl start

Service "cs11gR2" has 1 instance(s).

Instance "cs11gR2", status READY, has 1 handler(s) for this service...

The command completed successfully

DBA Team 16

Now query from RemoteC:\Documents and Settings\chensi4>sqlplus sid/sid@cs11gR2Connected to:Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing

options

SQL> select * from emp where ename='SMITH';

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO------- ------- ------- ----- --------- ----- ------ -------- 7369 SMITH CLERK 7902 17-DEC-80 800 20

1 row selected.

DBA Team 17

Listener

Server Processes

Client Processes

DataFiles

ControlFiles

Redo Log Files

Data Base

Instance







Check Point(CKPT)

LogWriter(LGWR)

Archiver(ARC0)


DBA Team 18

What Oracle Do

When you submit a SQL

1.From pl/sql develop2.From the JDBC API in your java application

3.From sqlplus

DBA Team 19

Parser

SELECT AVG(SAL) FROM EMP WHERE DEPTNO IN (SELECT DEPTNO FROM DEPT WHERE DNAME='SALES')

DBA Team 20

Parser

SELECT AVG(SAL) FROM EMP WHERE DEPTNO IN (SELECT DEPTNO FROM DEPT WHERE DNAME='SALES')

DBA Team 21

Query Transformer

Plan Generator

Data Dictionary

Estimator

SELECT AVG(SAL) FROM DEPT, EMP WHERE EMP.DEPTNO=DEPT.DEPTNO AND DEPT.DNAME='SALES';

Statistics

Transformed Query

Query + Cost

DBA Team 22

Query Transformer

Plan Generator

Data Dictionary

EstimatorStatistics

Transformed Query

Query + Cost

DBA Team 23

Row SourceGenerator

SQL Execution

Query Plan

Result

DBA Team 24

A Real Plan----------------------------------------------------------------------| Id | Operation | Name | Rows | Cost (%CPU)|----------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | 6 (17)|| 1 | SORT AGGREGATE | | 1 | || 2 | MERGE JOIN | | 5 | 6 (17)||* 3 | TABLE ACCESS BY INDEX ROWID| DEPT | 1 | 2 (0)|| 4 | INDEX FULL SCAN | DEPT_PK | 4 | 1 (0)||* 5 | SORT JOIN | | 14 | 4 (25)|| 6 | TABLE ACCESS FULL | EMP | 14 | 3 (0)|----------------------------------------------------------------------

Predicate Information (identified by operation id):---------------------------------------------------

3 - filter("DNAME"='SALES') 5 - access("DEPTNO"="DEPTNO") filter("DEPTNO"="DEPTNO")

DBA Team 25

Q & A

Oracle Basics and Architecture

Technology

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