09 creating an oracle database

8/12/2019 09 Creating an Oracle Database

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Revision no.: PPT/2K403/02

CMS INSTITUTE, 2004 . All rights reserved. No part of this material may be reproduced, stored or emailed without the prior permission of Programme Director, CMS Institute

2

Creation Prerequisites

Install the software. Creating the File System for the Database

Sizing the File system Space for the tables Space for the indexes Space for the undo tablespace

Space for the temporary tablespace Choosing the Location for the Files

Either by using OFA or manual.

Size the redo log files Ensuring enough Memory is allocated. Getting Necessary Authorizations.


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Operating System Environment

On UNIX set the following environment variables:

ORACLE_HOME ORACLE_SID

ORACLE_BASE

PATH

LD_LIBRARY_PATH


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Preparing the Parameter File

Create the new init.ora.

$cp init.ora $ORACLE_HOME/dbs/initU16.ora Modify the initU16.ora by editing the parameters.


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Starting the Instance

Connect as SYSDBA. Start the instance in NOMOUNT stage.

SQL> connect sys as sysdbaEnter password:Connected to an idle instance.

SQL> startup nomount

You can see all the background processes for your databaseinstance having been started at this point by using ps ef command.

At this point, go to the location of your bdump directory andsee the alert log file.

The alert log file gives you all the details of your instancecreation process.


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Creating the Database


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After Creation of the Database

Create additional tablespaces for user data.

Changing the Passwords for the Default Users

Changing the Archive Logging Mode.

Running the Pupbld.sql file.

Create a Server Parameter File ( spfile )


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The SPFILE Initialization Parameter

The SPFILE initialization parameter contains the name of the

current server parameter file.

When the default server parameter file is used by the server

(that is, you issue a STARTUP command and do not specify a

PFILE), the value of SPFILE is internally set by the server.

The SQL*Plus command SHOW PARAMETERS SPFILE

displays the name of the server parameter file that is currentlyin use.


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Using ALTER SYSTEM to Change InitializationParameter Values

The ALTER SYSTEM statement allows you to set, change, ordelete (restore to default value) initialization parameter values.

When the ALTER SYSTEM statement is used to alter aparameter setting in a traditional initialization parameter file,the change affects only the current instance, since there is no

mechanism for automatically updating initialization parameterson disk.

They must be manually updated in order to be passed to afuture instance.

Using a server parameter file overcomes this limitation.


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Setting or Changing Initialization ParameterValues

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What are Oracle-Managed Files?

Using Oracle-managed files simplifies the administration of anOracle database.

Oracle-managed files eliminate the need for you, the DBA, todirectly manage the operating system files comprising anOracle database.

You specify operations in terms of database objects rather

than filenames. Oracle internally uses standard file system interfaces to createand delete files as needed for the following databasestructures:

Tablespaces Online redo log files Control files

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What are Oracle-Managed Files? ( contd. )

Through initialization parameters, you specify the file system

directory to be used for a particular type of file.

Oracle then ensures that a unique file, an Oracle-managed file,

is created and deleted when no longer needed.

This feature does not affect the creation or naming of

administrative files such as trace files, audit files, alert files,

and core files.

Re ision no : PPT/2K403/02


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Enabling the Creation and Use of Oracle-Managed Files

DB_CREATE_FILE_DEST Defines the location of the default file system directory where

Oracle creates datafiles or tempfiles when no file specification isgiven in the creation operation.

Also used as a default file system directory for online redo log fileand control files if DB_CREATE_ONLINE_LOG_DEST_n is notspecified.

DB_CREATE_ONLINE_LOG_DEST_n Defines the location of the default file system directory for online

redo log files and control files when no file specification is givenin the creation operation.

You can use this initialization parameter multiple times, where nspecifies the multiplexed copy of the online redo log or controlfile.

You can specify up to 5 multiplexed copies.

Revision no : PPT/2K403/02


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How Oracle-Managed Files are Named

The filenames of Oracle-managed files comply with the Oracle

Flexible Architecture (OFA) standard for file naming.

The assigned names are intended to meet the following

requirements:

Database files are easily distinguishable from all other files.

Control files, online redo log files, and datafiles are identifiable as

such.

The association of datafile to tablespace is clearly indicated.



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How Oracle-Managed Files are Named (contd.)

No two Oracle-managed files are given the same name. The

name that is used for creation of an Oracle-managed file is

constructed from three sources.

The default file system directory location

A port-specific file name template that is chosen based on the

type of file

A unique string created by the Oracle database server or the

operating system. This ensures that file creation does not damage

an existing file and that the file cannot be mistaken for some other

file.



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Oracle-managed files have the followingformat on Solaris:

where: %t is the tablespace name.

At most, eight characters of the tablespace name are used. If eight characters causes the name to be too long, then the

tablespace name is truncated. Placing the tablespace name before the uniqueness string means that

all the datafiles for a tablespace appear next to each other in an

alphabetic file listing. %u is an eight character string that guarantees uniqueness %g is the online redo log file group number.



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Startup and Shutdown in Stages of theDatabase

OPENOPEN

MOUNTMOUNT

NOMOUNTNOMOUNT

SHUTDOWNSHUTDOWN

All files opened asAll files opened asdescribed by the controldescribed by the controlfile for thisfile for thisinstance.instance.

Control file openedControl file opened

for this instance.for this instance.

InstanceInstancestarted.started. S H

U T D O W

N

S H U T D

O W N

S T A R T

U P

S T A R T

U P



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Startup and Shutdown (contd.)

Starting an instance includes:

Reading the parameter file Allocating the SGA

Starting the background processes

Opening the ALERT and trace files



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STARTUP Command

Start up the instance, and open the database.

STARTUP [FORCE][RESTRICT][PFILE = filename][OPEN [RECOVER][database]| MOUNT| NOMOUNT]

STARTUP PFILE=/DISK1/initU15.oraSTARTUP PFILE=/DISK1/initU15.ora



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STARTUP Command

OPEN: enables users to access the database

MOUNT: mounts the database for certain activities but does

not allow user access to db

NOMOUNT: creates SGA + background processes; no accessto database

FORCE: aborts the running instance before performing anormal startup

RESTRICT: restricted access

RECOVER: begins media recovery



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ALTER DATABASE Command

Change state of the database from NOMOUNT to MOUNT ALTER DATABASE database MOUNT

Open the database as a read-only database ALTER DATABASE database OPEN READ ONLY



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Opening a Database in Read-Only Mode

Any database can be opened as a read-only database

A read-only database can be used to: Execute queries

Execute disk sorts

Take datafiles offline and online

Perform recovery of offline data files



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Shutdown Options

T

X

X

I

X

X

X

A

X

X

X

X

Shutdown Mode

Allow new connections

Wait until current sessions end

Wait until current transactions end

Force a checkpoint and close files

N

X

Shutdown mode:

A Abort I Immediate

T Transactional N Normal YES

NO



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Shutdown Time

ImmediateTransactionalTimeTime

Normal

Abort

4

3

1

2



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Quiescing a Database

There are times when there is a need to put a database into astate where only DBA transactions, queries, fetches, orPL/SQL statements are allowed.

This is called a quiesced state, in the sense that there are noongoing non-DBA transactions, queries, fetches, or PL/SQLstatements in the system.

This quiesced state allows you or other administrators toperform actions that cannot safely be done otherwise. To place a database into a quiesced state, issue the following

statement:

ALTER SYSTEM QUIESCE RESTRICTED; The following statement restores the database to normal

operation: ALTER SYSTEM UNQUIESCE;



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Quiescing a Database ( contd. )

These actions are categorized as follows:

Actions that can fail if concurrent user transactions access the

same object. For example, changing the schema of a database table or adding a

column to an existing table where a no-wait lock is required.

Actions whose undesirable intermediate effect can be seen byconcurrent user transactions.

For example, a multistep procedure for reorganizing a table where

the table is first exported, then dropped, and finally imported. A concurrent user who attempted to access the table after it was

dropped, but before import, would see disturbing results.



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Suspending and Resuming a Database

The ALTER SYSTEM SUSPEND statement suspends adatabase by halting all input and output (I/O) to datafiles (fileheader and file data) and control files, thus allowing adatabase to be backed up without I/O interference.

When the database is suspended all preexisting I/O operationsare allowed to complete and any new database accesses areplaced in a queued state.

The suspend command suspends the database, and is notspecific to an instance.

However, do not start a new instance while you suspend

another instance, since the new instance will not besuspended. Use the ALTER SYSTEM RESUME statement to resume normal

database operations.



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Dynamic Performance Views

Maintained by the Oracle Server and continuously updated

Contain data on disk and memory structures

Contain data that is useful for performance tuning

Have public synonyms with the prefix V$



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Accessing Dynamic Performance Views

OPENOPEN

MOUNTMOUNT

NOMOUNTNOMOUNT

Data dictionaryData dictionary

Dynamic performanceDynamic performance

views reading data fromviews reading data fromdiskdisk

DynamicDynamicperformanceperformanceviews reading fromviews reading frommemorymemorySHUTDOWNSHUTDOWN



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Example

V$PARAMETERV$SGAV$OPTION

V$PROCESSV$SESSIONV$VERSIONV$INSTANCE

Control file

SGA

V$THREADV$CONTROLFILEV$DATABASEV$DATAFILEV$DATAFILE_HEADERV$LOGFILE


Displaying Current


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Displaying CurrentParameter Values

Use the Server Manager command:

Query the dynamic performance view V$PARAMETER:

SHOW PARAMETER controlSHOW PARAMETER control

SELECT name FROM v$parameter

WHERE name LIKE %control%;

SELECT name FROM v$parameterWHERE name LIKE %control%;



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Dynamic Initialization Parameters

Some initialization parameters can be modified while aninstance is running.

ALTER SESSION SET SQL_TRACE=true; ALTER SESSION SET SQL_TRACE=true;

ALTER SYSTEM SET TIMED_STATISTICS=true; ALTER SYSTEM SET TIMED_STATISTICS=true;

ALTER SYSTEM SET SORT_AREA_SIZE=131072DEFERRED;

ALTER SYSTEM SET SORT_AREA_SIZE=131072DEFERRED;


Enable and Disable


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Enable and DisableRestricted Session

Use the STARTUP command to restrict access to a database:

Use the ALTER SYSTEM command to place an instance inrestricted mode:

STARTUP RESTRICTSTARTUP RESTRICT

ALTER SYSTEM ENABLE RESTRICTEDSESSION;

ALTER SYSTEM ENABLE RESTRICTEDSESSION;



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Terminating Sessions

Identify which session to terminate with the dynamicperformance view V$SESSION:

Execute the ALTER SYSTEM command:

SELECT sid, serial# FROM v$session WHEREusername=SCOTT;

SELECT sid, serial# FROM v$session WHEREusername=SCOTT;

ALTER SYSTEM KILL SESSION 7,15; ALTER SYSTEM KILL SESSION 7,15;



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Trace Files

Trace files can be written by server and backgroundprocesses.

Oracle dumps information about errors in trace files. The ALERT file consists of a chronological log of messages

and errors. Server process tracing can be enabled or disabled by:

An ALTER SESSION command The parameter SQL_TRACE

Check the ALERT file periodically to: Detect internal errors (ORA-600) and block corruption errors Monitor database operations View the nondefault initialization

parameter



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Important Oracle9i Initialization Parameters

Audit-Related Parameters

Database Name and Other General Parameters

File-Related Parameters

Oracle Managed Files Parameters

Process and Session Parameters Memory Configuration Parameters

Archive Log Parameters

Undo Space Parameters

Rollback Segment Parameters



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Important Oracle9i Initialization Parameters (contd )

Oracle Licensing-Related Parameters

Performance and Diagnostics Related Parameters

Recovery-Related Parameters

Data Block Verification Parameters

Security-Related Parameters

Undocumented Initialization Parameters



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Audit-Related Parameters

Audit_File_Dest specifies the directory where Oracle stores auditing files. Parameter type : String Syntax : AUDIT_FILE_DEST = 'directory' Default value : ORACLE_HOME/rdbms/audit Parameter class : Static

Audit_Trail enables or disables the automatic writing of rows to the audit trail. Parameter type : String

Syntax : AUDIT_TRAIL = {NONE | FALSE | DB | TRUE | OS} Default value : There is no default value. Parameter class : Static



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Audit-Related Parameters (contd )

Audit_Sys_Operations

enables or disables the auditing of operations issued by user

SYS, and users connecting with SYSDBA or SYSOPER privileges.

The audit records are written to the operating system's audit trail.

Parameter type : Boolean Default value : false

Parameter class : Static

Range of values : true | false



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Audit-Related Parameters (contd )

Transaction_Audit

If Transaction_Audit is true, Oracle generates a special redo

record that contains the user logon name, username, the session

ID, some operating system information, and client information.

Parameter type : Boolean Default value : true

Parameter class : Dynamic: ALTER SYSTEM ... DEFERRED




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Database Name and Other General Parameters

Db_Name specifies a database identifier of up to 8 characters. If specified, it must correspond to the name specified in the

CREATE DATABASE statement. Although the use of DB_NAME isoptional, you should generally set it before issuing the CREATEDATABASE statement, and then reference it in that statement.

The following characters are valid in a database name:alphanumeric characters, underscore (_), number sign (#), anddollar sign ($). No other characters are valid.

The database name is case insensitive. Parameter type : String Syntax : DB_NAME = database_name Default value : There is no default value. Parameter class : Static



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Database Name and Other General Parameters(contd )

Db_Domain In a distributed database system, Db_Domain specifies the logical

location of the database within the network structure.

You should set this parameter if this database is or ever will bepart of a distributed system.

The value consists of the extension components of a globaldatabase name, consisting of valid identifiers, separated by

periods. Oracle Corporation recommends that you specify DB_DOMAIN as

a unique string for all databases in a domain. Parameter type : String Syntax : DB_DOMAIN = domain_name Default value : There is no default value. Parameter class : Static



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Instance_Name

The instance_name parameter will have the same value as the

db_name parameter.

Parameter type : String

Syntax : INSTANCE_NAME = instance_id

Default value : The instance's SID




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Service_Names

specifies one or more names for the database service to which

this instance connects.


Syntax : SERVICE_NAMES = db_service_name [,

db_service_name [,...] ]

Default value : DB_NAME.DB_DOMAIN if defined Parameter class : Dynamic: ALTER SYSTEM



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Compatible

allows you to use a new release, while at the same time

guaranteeing backward compatibility with an earlier release. This

is helpful if it becomes necessary to revert to the earlier release.


Syntax : COMPATIBLE = release_number

Default value : 9.2.0.0.0



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Dispatchers

configures dispatcher processes in the shared server

architecture.

The parsing software supports a name-value syntax to enable the

specification of attributes in a position-independent case-

insensitive manner.


Syntax : DISPATCHERS = 'dispatch_clause

Default value : There is no default value.

Parameter class : Dynamic: ALTER SYSTEM


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Nls_Date_Format specifies the default date format to use with the TO_CHAR and

TO_DATE functions.

The default value of this parameter is determined byNLS_TERRITORY.

If the nls_territory format is America, the nls_date_formatparameter is automatically set to the DD-MON-YY format.

The value of this parameter can be any valid date format mask,and the value must be surrounded by double quotation marks.

For example: NLS_DATE_FORMAT = "MM/DD/YYYY" Parameter type : String Syntax : NLS_DATE_FORMAT = "format" Default value : Derived from NLS_TERRITORY Parameter class : Dynamic: ALTER SESSION



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File-Related Parameters (contd )

Control_Files Every database has a control file, which contains entries that

describe the structure of the database. Control_Files specifies one or more names of control files,

separated by commas. Oracle Corporation recommends that you multiplex multiple

control files. Parameter type : String Syntax : CONTROL_FILES = filename [, filename [...] ] Default value : Operating system-dependent Parameter class : Static Range of values : 1 to 8 filenames



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Db_Files specifies the maximum number of database files that can be

opened for this database.

The maximum valid value is the maximum number of files, subjectto operating system constraint, that will ever be specified for thedatabase, including files to be added by ADD DATAFILEstatements.

If you increase the value of DB_FILES, then you must shut downand restart all instances accessing the database before the newvalue can take effect.

Parameter type : Integer

Default value : 200 Parameter class : Static Range of values : operating system-dependent



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Core_Dump_Dest

is primarily a UNIX parameter and may not be supported on your

platform.

It specifies the directory where Oracle dumps core files.


Syntax : CORE_DUMP_DEST = d i rec tory

Default value : $ ORACLE_HOME /DBS




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User_Dump_Dest

specifies the pathname for a directory where the server will write

debugging trace files on behalf of a user process.


Syntax : USER_DUMP_DEST = { pa thname | d i rec tory }

Default value : Operating system-dependent




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Background_Dump_Dest

specifies the pathname (directory or disc) where debugging trace

files for the background processes (LGWR, DBWn, and so on) and

Oracle alert log files are written during Oracle operations.

Parameter type : String Syntax : BACKGROUND_DUMP_DEST = {pathname | directory}

Default value : Operating system-dependent




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Utl_File_Dir

lets you specify one or more directories that Oracle should use for

PL/SQL file I/O.


Syntax : UTL_FILE_DIR = pathname





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Oracle Managed Files Parameters

Db_Create_File_Dest

sets the default location for Oracle-managed datafiles.

This location is also used as the default for Oracle-managed

control files and online redo logs if

DB_CREATE_ONLINE_LOG_DEST_n is not specified.


Syntax : DB_CREATE_FILE_DEST = directory


Parameter class : Dynamic: ALTER SESSION, ALTER SYSTEM



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Oracle Managed Files Parameters (contd )

DB_CREATE_ONLINE_LOG_DEST_n

sets the default location for Oracle-managed control files and

online redo logs.


Syntax : DB_CREATE_ONLINE_LOG_DEST_[1 | 2 | 3 | 4 | 5] =

directory





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Process and Session Parameters (contd )

Processes specifies the maximum number of operating system user

processes that can simultaneously connect to Oracle.

Its value should allow for all background processes such aslocks, job queue processes, and parallel execution processes.

The default values of the SESSIONS and TRANSACTIONSparameters are derived from this parameter.

Therefore, if you change the value of PROCESSES, you shouldevaluate whether to adjust the values of those derivedparameters.


Default value : Derived from PARALLEL_MAX_SERVERS Parameter class : Static Range of values : 6 to operating system-dependent



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Db_Writer_Processes

is useful for systems that modify data heavily. It specifies the

initial number of database writer processes for an instance.


Default value : 1


Range of values : 1 to 20



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Sessions

specifies the maximum number of sessions that can be created in

the system. Because every login requires a session, this

parameter effectively determines the maximum number of

concurrent users in the system.


Default value : Derived: (1.1 * PROCESSES) + 5

Parameter class : Static Range of values : 1 to 231



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Open_Cursors

specifies the maximum number of open cursors (handles to

private SQL areas) a session can have at once. You can use this

parameter to prevent a session from opening an excessive

number of cursors


Default value : 50


Range of values : 1 to 4294967295 (4 GB -1)



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Memory Configuration Parameters

Db_Cache_Size specifies the size of the DEFAULT buffer pool for buffers with the

primary block size (the block size defined by the DB_BLOCK_SIZEparameter).

The value must be at least the size of one granule (smaller valuesare automatically rounded up to the granule size).

A value of zero is illegal because zero is the size of the DEFAULTpool for the standard block size, which is the block size for theSYSTEM tablespace.

Parameter type : Big integer

Syntax : DB_CACHE_SIZE = integer [K | M | G] Default value : 48 MB, rounded up to the nearest granule size Parameter class : Dynamic: ALTER SYSTEM



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Memory Configuration Parameters (contd )

Db_Keep_Cache_Size

specifies the size of the KEEP buffer pool.

The size of the buffers in the KEEP buffer pool is the primary

block size (the block size defined by the DB_BLOCK_SIZE

parameter).


Syntax : DB_KEEP_CACHE_SIZE = in teger [K | M | G]

Default value : 0 (KEEP cache is not configured by default) Parameter class : Dynamic: ALTER SYSTEM



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Db_nK_Cache_Size (where n = 2, 4, 8, 16, 32) specifies the size of the cache for the nK

buffers. You can set this parameter only when DB_BLOCK_SIZE has a

value other than nK. For example, if DB_BLOCK_SIZE=4096, then it is illegal to specify

the parameter DB_4K_CACHE_SIZE (because the size for the 4 KBblock cache is already specified by DB_CACHE_SIZE). Parameter type : Big integer Syntax : DB_[2 | 4 | 8 | 16 | 32]K_CACHE_SIZE = integer [K | M | G]

Default value : 0 (additional block size caches are not configuredby default)




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Shared_Pool_Size specifies (in bytes) the size of the shared pool. The shared pool consists of the data dictionary and the library

cache. The shared pool contains shared cursors, stored procedures,

control structures, and other structures. You can monitor utilization of the shared pool by querying the

view V$SGASTAT. Parameter type : Big integer Syntax : SHARED_POOL_SIZE = integer [K | M | G] Default value :

32-bit platforms: 16 MB, rounded up to the nearest granule size 64-bit platforms: 64 MB, rounded up to the nearest granule size




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Shared_Pool_Reserved_Size specifies (in bytes) the shared pool space that is reserved for

large contiguous requests for shared pool memory.

You can use this parameter to avoid performance degradation inthe shared pool in situations where pool fragmentation forcesOracle to search for and free chunks of unused pool to satisfy thecurrent request.

Parameter type : Big integer Syntax : SHARED_POOL_RESERVED_SIZE = integer [K | M | G] Default value : 5% of the value of SHARED_POOL_SIZE Parameter class : Static Range of values :

Minimum: 5000 Maximum: one half of the value of SHARED_POOL_SIZE



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Pga_Aggregate_Target specifies the target aggregate PGA memory available to all server

processes attached to the instance.

You must set this parameter to enable the automatic sizing of SQLworking areas used by memory-intensive SQL operators such assort, group-by, hash-join, bitmap merge, and bitmap create.

Oracle uses this parameter as a target for PGA memory.

Parameter type : Big integer Syntax : PGA_AGGREGATE_TARGET = integer [K | M | G] Default value : 0 (automatic memory management is turned OFF

by default) Parameter class : Dynamic: ALTER SYSTEM Range of values :

Minimum: 10 MB Maximum: 4096 GB - 1



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Log_Buffer specifies the amount of memory (in bytes) that Oracle uses when

buffering redo entries to a redo log file.

Redo log entries contain a record of the changes that have beenmade to the database block buffers.

The LGWR process writes redo log entries from the log buffer to aredo log file.

In general, larger values for LOG_BUFFER reduce redo log file I/O,particularly if transactions are long or numerous. In a busysystem, a value 65536 or higher is reasonable.


Default value : 512 KB or 128 KB * CPU_COUNT, whichever isgreater

Parameter class : Static Range of values : Operating system-dependent


f


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Large_Pool lets you specify the size (in bytes) of the large pool allocation heap. The large pool allocation heap is used in shared server systems for

session memory, by parallel execution for message buffers, and bybackup processes for disk I/O buffers.

(Parallel execution allocates buffers out of the large pool only whenPARALLEL_AUTOMATIC_TUNING is set to true.)

Parameter type : Big integer Syntax : LARGE_POOL_SIZE = integer [K | M | G] Default value : 0 if both of the following are true:

The pool is not required by parallel execution

DBWR_IO_SLAVES is not set Parameter class : Dynamic: ALTER SYSTEM Range of values : 300 KB to at least 2 GB (actual maximum is operating

system-specific)


f


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Java_Pool_Size specifies the size (in bytes) of the Java pool, from which the Java

memory manager allocates most Java state during runtime

execution. This memory includes the shared in-memory representation of

Java method and class definitions, as well as the Java objectsthat are migrated to the Java session space at end-of-call.

Parameter type : Big integer Syntax : LARGE_POOL_SIZE = integer [K | M | G] Default value : 24 MB, rounded up to the nearest granule size Parameter class : Static Range of values :

Minimum: the granule size Maximum: operating system-dependent


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Sga_Max_Size

specifies the maximum size of SGA for the lifetime of the instance.


Syntax : SGA_MAX_SIZE = in teger [K | M | G]

Default value : Initial size of SGA at startup, dependent on thesizes of different pools in the SGA, such as buffer cache, shared

pool, large pool, and so on.

Parameter class : Static Range of values : 0 to operating system-dependent


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Lock_Sga

locks the entire SGA into physical memory.

It is usually advisable to lock the SGA into real (physical) memory,especially if the use of virtual memory would include storing some

of the SGA using disk space.

This parameter is ignored on platforms that do not support it.

Parameter type : Boolean

Default value : false




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Db_Cache_Advice

enables or disables statistics gathering used for predicting

behavior with different cache sizes through theV$DB_CACHE_ADVICE performance view.


Syntax : DB_CACHE_ADVICE = {ON | READY | OFF}

Default value :

If STATISTICS_LEVEL is set to TYPICAL or ALL, then ON

If STATISTICS_LEVEL is set to BASIC, then OFF



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Archive Log Parameters

Log_Archive_Dest_n

parameters (where n = 1, 2, 3, ... 10) define up to ten archive log

destinations. The parameter integer suffix is defined as the handledisplayed by the V$ARCHIVE_DEST dynamic performance view.


Syntax : LOG_ARCHIVE_DEST_n = { null_string} | {LOCATION=path_name | SERVICE=service_name } [ {

MANDATORY | OPTIONAL } ]




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Archive Log Parameters (contd )

Log_Archive_Start

is applicable only when you use the redo log in ARCHIVELOG

mode. It indicates whether archiving should be automatic ormanual when the instance starts up.

The SQL*Plus statements ARCHIVE LOG START or ARCHIVE LOG

STOP override this parameter. Parameter type : Boolean





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Archive Log Parameters (contd )

Log_Archive_Format is applicable only if you are using the redo log in ARCHIVELOG

mode.

The string generated from this format is appended to the stringspecified in the LOG_ARCHIVE_DEST parameter. The following variables can be used in the format:

%s log sequence number

%S log sequence number, zero filled %t thread number %T thread number, zero filled

Parameter type : String Syntax : LOG_ARCHIVE_FORMAT = filename Default value : Operating system-dependent Parameter class : Static Range of values : Any string that resolves to a valid filename


U d S P t


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Undo_Tablespace specifies the undo tablespace to be used when an instance starts up. If this parameter is specified when the instance is in manual undo

management mode, an error will occur and startup will fail. If no undo tablespace is available, the instance will start without an

undo tablespace. In such cases, user transactions will be executedusing the SYSTEM rollback segment.

You can replace an undo tablespace with another undo tablespacewhile the instance is running.

Parameter type : String Syntax : UNDO_TABLESPACE = undoname Default value : The first available undo tablespace in the database. Parameter class : Dynamic: ALTER SYSTEM Range of values : Legal name of an existing undo tablespace




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Undo Space Parameters (contd )

Undo_Management

specifies which undo space management mode the system

should use. When set to AUTO, the instance starts in automatic undo

management mode.

In manual undo management mode, undo space is allocatedexternally as rollback segments.


Syntax : UNDO_MANAGEMENT = {MANUAL | AUTO}

Default value : MANUAL





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Undo Space Parameters (contd )

Undo_Retention specifies (in seconds) the amount of committed undo information

to retain in the database.

You can use UNDO_RETENTION to satisfy queries that require oldundo information to rollback changes to produce older images ofdata blocks.

The UNDO_RETENTION parameter works best if the current undotablespace has enough space for the active transactions.


Default value : 900 Parameter class : Dynamic: ALTER SYSTEM

Range of values : 0 to 232-1 (max value represented by 32 bits)


Oracle Licensing Related Parameters


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Oracle Licensing-Related Parameters

License_Max_Users specifies the maximum number of users you can create in the

database. When you reach this limit, you cannot create more users. You can,

however, increase the limit. Do not enable both concurrent usage (session) licensing and user

licensing. Set either LICENSE_MAX_SESSIONS or LICENSE_MAX_USERS

to zero. Parameter type : Integer

Default value : 0 Parameter class : Dynamic: ALTER SYSTEM Range of values : 0 to number of user licenses


Oracle Licensing Related Parameters


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Oracle Licensing-Related Parameters (contd )

License_Max_sessions

specifies the maximum number of concurrent user sessions

allowed. When this limit is reached, only users with the RESTRICTED

SESSION privilege can connect to the database.

Users who are not able to connect receive a warning messageindicating that the system has reached maximum capacity.


Default value : 0


Range of values : 0 to number of session licenses

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Parameters

Optimizer_Mode establishes the default behavior for choosing an optimization

approach for the instance. You can set the optimizer mode to rule-based, first_rows,

first_rows_n, all_rows, or choose. If you set it to choose, Oracle will use the cost based optimizer if

the statistics exist for the tables involved in the query. Parameter type : String Syntax :

OPTIMIZER_MODE = {first_rows_[1 | 10 | 100 | 1000] | first_rows |

all_rows | choose | rule} Default value : choose Parameter class : Dynamic: ALTER SESSION

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Parameters (contd )

Query_Rewrite_Enabled

allows you to enable or disable query rewriting globally for the

database, which is of importance mostly when you usematerialized views.

You can create materialized views only by setting this parameter to true.


Syntax : QUERY_REWRITE_ENABLED = {force | true | false}



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Parameters (contd )

Query_Rewrite_Integrity

determines the degree to which Oracle must enforce query

rewriting. At the safest level, Oracle does not use query rewrite

transformations that rely on unenforced relationships.

Parameter type : String Syntax :

QUERY_REWRITE_INTEGRITY = {stale_tolerated | trusted | enforced}

Default value : enforced




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Parameters (contd )

Star_Transformation_Enabled

determines whether a cost-based query transformation will be

applied to star queries ( data warehouse). Parameter type : String

Syntax :

STAR_TRANSFORMATION_ENABLED = {TEMP_DISABLE | TRUE |

FALSE}

Default value : FALSE

Parameter class : Dynamic: ALTER SESSION



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Parameters (contd )

Cursor_Sharing

determines what kind of SQL statements can share the same

cursors.

The three possible values are forced, exact and similar.

Parameter type : String Syntax : CURSOR_SHARING = {SIMILAR | EXACT | FORCE}

Default value : EXACT


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Parameters (contd )

Cursor_Space_For_Time

lets you use more space for cursors in order to save time. It

affects both the shared SQL area and the client's private SQL

area.





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Parameters (contd )

Db_Block_Size specifies the size (in bytes) of Oracle database blocks.

Typical values are 2048 and 4096. The value for DB_BLOCK_SIZE in effect at the time you create the

database determines the size of the blocks.

The value must remain set to its initial value.


Default value : 2048


Range of values : 2048 to 32768, but your operating system mayhave a narrower range



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Parameters (contd )

Db_File_Multiblock_Read_Count is one of the parameters you can use to minimize I/O during table

scans.

It specifies the maximum number of blocks read in one I/Ooperation during a sequential scan.

The total number of I/Os needed to perform a full table scandepends on such factors as the size of the table, the multiblockread count, and whether parallel execution is being utilized for theoperation.


Default value : 8 Parameter class : Dynamic: ALTER SESSION, ALTER SYSTEM Range of values : Operating system-dependent



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Parameters (contd )

Oracle_Trace_Enable

To enable Oracle Trace collections for the server, set

Oracle_Trace_Enable to true.

This setting alone does not start an Oracle Trace collection, but it

allows Oracle Trace to be used for the server.







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Parameters (contd )

Sql_Trace

The value of Sql_Trace disables or enables the SQL trace facility.

Setting this parameter to true provides information on tuning that

you can use to improve performance.

Parameter type : Boolean Default value : false





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Parameters (contd )

Parallel_Automatic_Tuning

When Parallel_Automatic_Tuning is set to true, Oracle determines

the default values for parameters that control parallel execution. In addition to setting this parameter, you must specify the

PARALLEL clause for the target tables in the system.

Oracle then tunes all subsequent parallel operationsautomatically.







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Parameters (contd )

Parallel_Max_Servers specifies the maximum number of parallel execution processes and

parallel recovery processes for an instance.

As demand increases, Oracle increases the number of processes from thenumber created at instance startup up to this value.

If you set this parameter too low, some queries may not have a parallelexecution process available to them during query processing.

If you set it too high, memory resource shortages may occur during peakperiods, which can degrade performance.

Parameter type : Integer Default value : Derived from the values of CPU_COUNT,

PARALLEL_AUTOMATIC_TUNING, andPARALLEL_ADAPTIVE_MULTI_USER Parameter class : Static Range of values : 0 to 3599



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Parameters (contd )

Timed_Statistics specifies whether or not statistics related to time are collected.

On some systems with very fast timer access, Oracle mightenable timing even if this parameter is set to false.

On these systems, setting the parameter to true can sometimesproduce more accurate statistics for long-running operations


Default value : If STATISTICS_LEVEL is set to TYPICAL or ALL, then true

If STATISTICS_LEVEL is set to BASIC, then false Parameter class : Dynamic: ALTER SESSION, ALTER SYSTEM




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Parameters (contd )

Resource_Limits

determines whether resource limits are enforced in database

profiles


Default value : false Parameter class : Dynamic: ALTER SYSTEM




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Parameters ( )

Workarea_Size_Policy

specifies the policy for sizing work areas. This parameter controls

the mode in which working areas are tuned.


Syntax : WORKAREA_SIZE_POLICY = {AUTO | MANUAL}

Default value :

If PGA_AGGREGATE_TARGET is set, then AUTO

If PGA_AGGREGATE_TARGET is not set, then MANUAL Parameter class : Dynamic: ALTER SESSION, ALTER SYSTEM


Recovery-Related Parameters


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ecove y e ated a a ete s

Fast_Start_Mttr_Target

enables you to specify the number of seconds the database takes

to perform crash recovery of a single instance. When specified, FAST_START_MTTR_TARGET

Is overridden by FAST_START_IO_TARGET

Is overridden by LOG_CHECKPOINT_INTERVAL


Default value : 0


Range of values : 0 to 3600 seconds


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Recovery-Related Parameters (contd )


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y ( )

Control_File_Record_Keep_Time specifies the minimum number of days before a reusable record in

the control file can be reused.

In the event a new record needs to be added to a reusable sectionand the oldest record has not aged enough, the record sectionexpands.

If this parameter is set to 0, then reusable sections never expand,and records are reused as needed.


Default value : 7 (days) Parameter class : Dynamic: ALTER SYSTEM

Range of values : 0 to 365 (days)


Data Block Verification Parameters


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Db_Block_Checksum determines whether DBWn and the direct loader will calculate a

checksum and store it in the cache header of every data block

when writing it to disk. If this parameter is set to false, DBWn calculates checksums only

for the SYSTEM tablespace, but not for user tablespaces. This parameter checks all the data blocks on disks for the Oracle

redo log files. By using checksums written to the data file headers, Oracle can

check for corrupted redo logs if you turn this parameter on. Parameter type : Boolean

Default value : true Parameter class : Dynamic: ALTER SYSTEM Range of values : true | false


Data Block Verification Parameters (contd )


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Db_Block_Checking

controls whether Oracle performs block checking for data blocks.

When this parameter is set to true, Oracle performs blockchecking for all data blocks.

When it is set to false, Oracle does not perform block checkingfor blocks in the user tablespaces.

Block checking for the SYSTEM tablespace is always turned on.


Default value : false Parameter class : Dynamic: ALTER SESSION, ALTER SYSTEM



Security-Related Parameters


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101

y

Os_Authent_Prefix specifies a prefix that Oracle uses to authenticate users

attempting to connect to the server.

Oracle concatenates the value of this parameter to the beginningof the user's operating system account name and password.

When a connection request is attempted, Oracle compares theprefixed username with Oracle usernames in the database.

The default value of this parameter is OPS$ for backwardcompatibility with previous versions.


Syntax : OS_AUTHENT_PREFIX = authentication_prefix Default value : OPS$ Parameter class : Static


Security-Related Parameters (contd )


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y

Remote_Login_Passwordfile specifies whether Oracle checks for a password file and how

many databases can use the password file.

Parameter type : String Syntax : REMOTE_LOGIN_PASSWORDFILE= {NONE | SHARED |

EXCLUSIVE} Default value : NONE

Parameter class : Static NONE : Oracle ignores any password file. Therefore, privileged

users must be authenticated by the operating system. SHARED : More than one database can use a password file.

However, the only user recognized by the password file is SYS. EXCLUSIVE : The password file can be used by only one database

and the password file can contain names other than SYS.


Undocumented Initialization Parameters


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In addition to the initialization parameters listed, Oracle hasseveral undocumented initialization parameters.

These parameters are not supposed to be altered in any wayby regular users; therefore they remain undocumented.

The following query produces a list of 540 undocumentedparameters for the Oracle 9.2.0.1.0 database version. select a.ksppinm parameter, a.ksppdesc description,

b.ksppstvl session_value, c.ksppstvl instance_valuefrom x$ksppi a, x$ksppcv b, x$ksppsv c

where a.indx = b.indx and a.indx = c.indx andsubstr(a.ksppinm,1,1) = '_ order by a.ksppinm

/


Exercise II Create the Database


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09 creating an oracle database

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