Oracle Database Administration for Microsoft SQL Server DBAs part 13 pot

Since there is one Oracle database server for an Oracle instance, creating an Oracle database requires a good bit of configuration and planning.. Users are added only to the Oracle datab

A new role with the select permissions could be created for each of the represented DBA roles, which would limit full access to the database based

on responsibility Even if there is only one DBA, creating a different user with some of the basic permissions for a DBA would be better than always logging in as SYSDBA

Summary

In this chapter, we first looked at some database terminology used by the different platforms You saw that the SQL Server database is more similar to the Oracle schema than to the Oracle database Since there is one Oracle database server for an Oracle instance, creating an Oracle database requires

a good bit of configuration and planning

Several assistants are available to create a database, upgrade a database, create a listener, create scripts and templates for the database, and set up the OEM The assistants provide an interface to be able to walk through the different steps, and allow for configuration and customizations along the way

Database scripts and templates can be used to re-create the same

database or to clone the database in another environment The scripts can also be modified to create a new database with similar characteristics The DBCA is a good tool for creating a database for a new Oracle version and taking the defaults to see what some of the new default parameters and configurations might be This could help in planning upgrades and

acceptance of new features

Security is another important topic when it comes to databases, and setting up permissions for least privilege is a database standard Users are added only to the Oracle database server, and then granted permissions to create objects in their schemas or have access to other schema objects There are some system roles for just the DBAs to use with caution

Access to the database can be handled in several different ways Also, determining who has permissions to create objects and manipulate data can

be based on application security and other security policies and standards

In discussing the creation assistants in this chapter, we have already started to look at some of the Oracle tools In the next chapter, we’ll

continue to explore the tools that are provided to aid DBAs in an Oracle environment

102 Oracle Database Administration for Microsoft SQL Server DBAs

DBA Tools

I n the previous chapters, we’ve covered installing Oracle andcreating the database The next chapters will move on to specific

Oracle database administration tasks Here, we will take a look at the tools available for performing these tasks

What do I mean by “tool”? It’s true that even a simple SQL statement that is saved to be reused can be considered a tool And, yes, we could be writing Perl and shell scripts to manage everything But we’ll focus on some

of the Oracle-provided tools that make the job a little easier, and some good checks and verification steps to do when using these tools Note that tools from third-party vendors are available, and although they are not included

in this discussion, some are also quite useful for DBAs

Overview of Tools for Typical

Database Tasks

Table 5-1 shows the main tools in SQL Server and Oracle for performing some common DBA tasks

104 Oracle Database Administration for Microsoft SQL Server DBAs

Get an overview of

objects and database

activity

SQL Server Management Studio

Oracle Enterprise Manager

Run queries SQL Server Management

Studio, Query Analyzer

SQL Developer, SQL*Plus, SQL Worksheet

Trace sessions Profiler Oracle Enterprise

Manager, v$ views Back up databases Maintenance Plans, SQL

Server Management Studio

Oracle Recovery Manager, Oracle Enterprise Manager Monitor SQL Server Management

Studio

Oracle Enterprise Manager, v$ views Schedule SQL Server Agent, SQL

Server Management Studio

Oracle Scheduler, Oracle Enterprise Manager

TABLE 5-1. DBA Tools for Common Tasks

You can see from the table that both SQL Server and Oracle provide a

main tool for database administration: SQL Server Management Studio and

Oracle Enterprise Manager (OEM) Let’s start with a look at OEM

Oracle Enterprise Manager

OEM is similar to SQL Server Management Studio in that it gives you a look

at the server information, error logs, scheduled tasks, and object information

OEM also provides some operating system information and performance

statistics OEM offers an easy view into a database and provides the ability

to manage the database in a GUI

NOTE

Managing multiple databases in an enterprise

environment is better left to the Grid Control,

rather than the single instance of the Database

Control However, the Database Control for a

single database is a good starting point for

understanding the templates and setup for

monitoring

OEM Navigation

OEM has come a long way since it was first introduced With the improvements

in OEM, there have been many changes to where things appear within the

tool Even from OEM 11g R1 to R2, a few categories have been rearranged

Some of these changes come directly from recommendations by users,

based on how they use features So change is good, but explaining where

to find different options and administration tasks is more difficult, since it

depends on the version However, although a tool may be in a different

place in the various versions, its header or description will be very similar

The first page that appears after logon provides some basic information

about the system being up and available, any new alerts in the error log, the server name and listener, and if using ASM, the ASM instance information

The tabs and categories changed from Oracle Database 10g to 11g, but you can still navigate from this home page to the areas to manage the server and perform administration tasks

The tabs do a good job of describing the areas that are available:

■ Performance The Performance tab has some graphs that show the

active sessions, CPU utilization, and throughput statistics It has links

to drill down into the top sessions, currently running SQL, and a view to check if there is any blocking These areas will allow for some tuning of queries and the current activity

■ Availability The Availability tab has the backup and recovery tasks.

We will look at these options and settings in the next chapter

■ Server The Server tab contains tasks such as scheduling jobs,

setting up security, configuring parameters, and managing storage and statistics This area is probably the closest to the information in properties for a SQL Server instance, as well as the database properties that are seen in SQL Server Management Studio

■ Schema The Schema tab provides a view into the objects in the

schemas The tables, indexes, views, packages, procedures, triggers, materialized views, defined types, and other objects are available to view by schema After drilling down to an object, such as a table, the object can be edited or new objects of that type can be created The Schema tab is similar to the Object Explorer for SQL Server Management Studio, but it also offers the functionality to walk through the tasks, step by step Additionally, you can view the SQL statements to perform the tasks, which can be executed in other tools

■ Data Movement As the name suggests, the Data Movement tab

has steps for exporting and importing data There is also a Streams category, which is for the setup and management of replication

■ Software and Support The Software and Support tab includes details

on the host configuration and the Oracle Inventory, including the version of the installed Oracle software There is a section for patching, with a way to stage and apply patches The Real Application Testing option allows for replay of the database activity to test a patch rollout, upgrade, or new deployment of configurations

106 Oracle Database Administration for Microsoft SQL Server DBAs

In SQL Server, after installation of an instance, you launch SQL Server

Management Studio to verify and adjust settings, create users, and configure the instance for the needed databases The options and configurations available

in properties of the SQL Server instance correspond to the properties that are

available in the Server tab of OEM, as shown in Figure 5-1 After creating the

database, the Server tab of OEM is a good place to start to add users, create user tablespaces, and verify the parameter settings Most of the server setup and

configurations are under the Server tab, and by exploring the categories, you

can learn how to navigate through the OEM to perform the needed tasks So,

let’s take a closer look at the Server tab

Storage Management

Under the Storage category, the Tablespaces section will list the system

tablespaces that have been created: SYSTEM, SYSAUX, TEMP, UNDO, and

FIGURE 5-1. OEM Server tab

probably USER as well You can adjust the defaults for sizing the tablespaces and add new tablespaces, for an application or for a schema Having

different tablespaces helps to organize the objects in the database This organization used to be mainly by tables and indexes, but now it can be more about usage and how and when the tablespaces are being accessed You can size the tablespaces based on initial estimates when you create them, and then use OEM to watch their growth and see if more disk is needed From the Control Files section under Storage, you can back up the control file, which is part of a backup strategy, as discussed in the next chapter The last change number is here with the database ID, which is important information about the database, particularly if you need to recover the database

Redo logs can be managed from here as well The Redo Log Groups section shows the current log file Here, you can add groups or add

members to the groups

NOTE

It is good practice to name redo logs with an

extension other than log, even though that is

the Oracle default Use something like rdo or

.ldf to make sure that these are treated like

critical database files, rather than output logs

Database Configuration

Under the Database Configuration category, the Initialization Parameters section lists the database parameters You can verify and adjust these

parameters as needed You can also modify the way that the parameters are listed, so that they are divided by basic, dynamic, or categories (such as memory) to give a more meaningful grouping of the parameters—the whole listing of all the parameters can be overwhelming

The View Database Feature Usage section shows the installed components After the database is up and running, it will show which components are actually being used This is useful information for patching and testing the areas in use If some installed components are not being used, you may want

to consider disabling those components

The Memory Advisors section is the place to go to view how memory is being allocated and managed It shows statistics about the memory Obviously, viewing this section after there is load on the database will provide more valuable information than looking at it immediately after database startup

108 Oracle Database Administration for Microsoft SQL Server DBAs

Oracle Scheduler

The Oracle Scheduler category provides information similar to what you

find in the SQL Server Agent and Job Activity Monitor in SQL Server

Management Studio

The Jobs section lists all of the jobs that run against the database You

can view and edit the job description and properties The jobs can also be

run from here, and you can view the history of the job and the schedule

The Automated Maintenance Tasks section lists tasks such as statistics

gathering and possibly backups This is different from how these tasks are

handled in SQL Server, which has the Maintenance Plans feature for setting

up backups and statistics gathering This feature is found under Management,

rather than with the jobs and schedules

Statistics and Resource Management

The Statistics Management category offers a view into the workload repository

These are statistics that are collected for sessions and processes running

against the database The repository pulls together the information to help

assess the database performance, with top wait events, top SQL sessions,

cache hit ratios, and several other statistics

SQL Server 2008 introduced a new Resource Governor, under the

Management folder In Oracle, Resource Manager has been around for

a few versions The Resource Manager category on the Server tab has

sections for setting up consumer groups and plans

Security

The Security category provides access to security-related areas Under

Users, all of the system users are listed, and the list might be longer than

expected, depending on the components and examples installed Many of

the users might be locked and expired, which is the default security for the

components You can activate the user accounts you need and change their

passwords You can also create new users, either as a copy of an existing

user or as a completely new user

When creating users that will be allowed to create tables and indexes,

keep in mind that they will need a quota on a tablespace—just setting a

default tablespace will not be enough Even with the permissions to create

a table or index, without access to a tablespace, users will receive an error when they try to create the object:

SQL> create table example1

(object_id number,

object_desc varchar2(20));

create table example1

*

ERROR at line 1:

ORA-01950: no privileges on tablespace 'USERS'

Figure 5-2 shows an example of a USER tablespace quota being set for a new user The quota can be a specific value or be set to unlimited You can also edit an existing account to set the quota

Even though the UNDO and TEMP tablespaces are listed as options here, you cannot grant a quota on these tablespaces, as they are used for transactions and available to all of the users If you try, you will get an “ORA-30041: Cannot grant quota on the tablespace” error You can grant quotas on the SYSTEMand SYSAUX tablespaces, but this is not recommended, because those areas should be used for system objects

110 Oracle Database Administration for Microsoft SQL Server DBAs

FIGURE 5-2. Setting a USER tablespace quota

Enterprise Manager Configuration

One other area to look at under the Server tab is Enterprise Manager

Administration The agent and dbconsole process were created with the

creation of the database Here, you can configure notifications, set

thresholds for monitoring, and set blackouts

Figure 5-3 shows the Administrators section, which lists the system

administrators who can log in to OEM to perform management tasks A new administrator account can be created outside the system accounts, with

fewer privileges, to allow administrators to manage templates, blackouts,

and notifications (a good practice to follow for a secure implementation)

The other sections show setup information for OEM The Management

Pack Access section lists some of the database packs which are options and

may require additional licensing

This was just a brief overview of some of the areas of OEM to get you

started with this tool Next, we’ll look at SQL*Plus, a tool for managing

database objects

When Do You Need Quotas?

You do not need to set tablespace quotas for users if they will just be

performing transactions on that table—selecting, inserting, updating,

and deleting However, if the schema owner had a set quota of 2GB

and a user attempted to insert 3GB of data, that user might receive an

“exceeded quota” error on the transaction

Quotas are just needed to create tables or indexes in tablespaces

Procedures and functions do not need tablespaces, so a user that will

be creating these objects might not have quotas on tablespaces

There is a system privilege of unlimited tablespace, which grants

a user unlimited access to all of the tablespaces, including system

tablespaces So you can see why it’s a good idea to just grant access to

the specific tablespaces, instead of opening up the system tablespace

for some random object from a user