Week 1Lecture 2

Overview of Database Administrator (DBA) Tools

Objectives

Identify the main DBA tools in the Oracle9i software suite

Configure Oracle Net to connect to the database

List the memory and background process components of the database instance

Start using the Enterprise Manager

Overview of DBA tools

Tools can be started from the console or as stand-alone components.

Important tools to know:

• Database Configuration Assistant

• Enterprise Manager Console

• Log Miner

• Net Manager and Net Configuration Assistant

• SQL*Plus and SQL*Plus Worksheet

Overview of DBA tools

Important operating system commands:

Tool name UNIX command Windows command

Enterprise Manager console

oemapp console oemapp.bat console

SQL*Plus sqlplus <user>/<pwd> sqlplus <user>/<pwd>

Net Manager netmgr netmgr

SQL*Plus Worksheet

oemapp worksheet oemapp.bat worksheet

Configuring Oracle Net: Architecture

Oracle Net must be configured on both the client and the server when using Oracle tools on the client side.

Configuring Oracle Net: Architecture

Three methods of connecting:Oracle NetJDBC thin driverBequeath protocol

Configuring Oracle Net: Net Manager

Use Net Manager to configure Oracle Net

A service name defines the database’s name, location, and listening port

Net Manager contains a wizard to configure a new service name

The file tnsnames.ora stores Oracle Net configuration settings

Oracle Memory and Background Processes: Connecting to a Shared Server

Red lines trace the path between the client and the instance

Oracle Memory and Background Processes: Connecting to a Dedicated Server

Red lines trace the path between the client and the instance

Oracle Memory : PGA & SGA

The PGA has private areas for each application

The SGA is allocated when the instance starts up

Oracle Memory : SGA Components

The shared pool stores parsed SQL commands for possible reuse

The buffer cache stores data blocks read from the datafiles

Oracle Memory: SGA Components

The cursor pool is optional and provides extra memory for program cursors

The redo log buffer stores all changes to data before the changes are written to the datafiles

The large pool is optional and adds more memory for better response time

Background Processes: PMON & SMON

PMON (Process Monitor) cleans up remaining resourcesafter the server and user processes end

SMON (System Monitor) handles recovery if needed, cleans up old temporary tables, and restores space

Background Processes: DBWn & CKPT

DBWn (Database Writer) writes modified buffers to the datafiles

CKPT (Checkpoint Process) signals the DBWn process and assigns SCN

Background Processes: ARCn & LGWR

ARCn (Archiver) copies redo log files to archive log files

LGWR (Log Writer) writes redo log buffers to the redo log files

Background Processes: RECO & LMS

RECO (Recoverer Process) fixes errors if changes across distributed databases fail

LMS (Lock Manager Service) handles updates that affect data in multiple clustered databases

Introducing Enterprise Manager

Central clearinghouse of DBA tools

Windows-like interface with little or no SQL coding required

Centered around the Enterprise Manager console

Optionally, uses the Enterprise Management Server

Enterprise Manager console

Important features

Enterprise Manager: Instance Manager

Instance Manager handles these tasks (and more):

Setting initialization parameters

Starting and shutting down the database

Monitoring and adjusting memory usage

Locating redo log files

Enterprise Manager: Schema Manager

Schema Manager handles these tasks (and more):

Adding and removing columns on tables or views

Creating new tables, indexes, views, and object types

Adding constraints to tables

Viewing statistics on tables

Enterprise Manager: Security Manager

Security Manager handles these tasks (and more):

Creating new users and roles

Changing user passwords

Assigning and revoking user privileges

Adjusting user storage quotas

Enterprise Manager: Storage Manager

Storage Manager handles these tasks (and more):

Creating new tablespaces

Adjusting size of data files

Taking tablespaces offline

Monitoring storage usage

Lecture Summary Oracle’s DBA tools are available inside the Enterprise

Manager console or stand-alone

Oracle Net is the most common way to communicate between client and database server

Other methods of communicating are JDBC driver and Bequeath protocol

Net Manager provides a tool for configuring Oracle Net

The tnsnames.ora file stores Oracle Net configuration information

Lecture Summary

Database servers are either in shared server mode or dedicated mode

User processes and server processes handle connections and user sessions

Oracle memory is made up of the PGA and the SGA

The PGA has private areas for each application

The SGA is part of the database instance

Lecture Summary

The SGA stores data blocks read from the data files and stores changed data blocks

The background processes run the database functions such as reading and writing datafiles

The Enterprise Manager console is the center of Oracle’s DBA tool set

The console can run stand-alone or as part of the Enterprise Management Server

Lecture Summary

The four main tools within the Enterprise Management console are:

Instance Manager

Schema Manager

Security Manager

Storage Manager