My notes for teaching the OCA 11g DBAI class, for students preparing to take the OCA exam. 

Database Writer writes when:

1. No free buffers
2. Too many dirty buffers
3. 3 second timout
4. Checkpoint

Log Writer writes when:

1. session COMMIT
2. buffer 1/3 full
3. DBWR is about to write

UNDO

UNDO is used for:

1. Reversing incomplete transactions
2. Read consistency (temporary)
3. Transaction isolation
4. Flashback (9i temporary)

UNDO errors:

Run out of space ORA-30036 “unable to extend segment in undo tablespace”  Lets the query succeed

Fails on consistent read- undot for CR has been overwritten ORA-01555 “snapshot too old”. This means the transaction will succeed.

FAILURE TYPES

1. Statement failure
2. User process failure- Network(listener, network card, route), User error
3. Media Failure
4. Instance Failure

RECOVERY

1. Loss of control file
2. Loss of online redo log
3. Loss of datafile in NOARCHIVELOG mode
4. Loss of datafile in ARCHIVELOG mode

Init parameters

FAST_START_MTTR_TARGET

Views

V$INSTANCE_RECOVERY

Commands

alter system checkpoint

alter system switch logfile

FLASHBACK

db_file_recovery_dest

db_file_recovery_dest_size

V$RECOVERY_FILE_DEST

V$FLASH_RECOVERY_USAGE

How to Set Archive Log Mode

1. ARCHIVE LOG LIST
2. Shutdown
3. ALTER DATABASE ARCHIVELOG
4. ALTER SYSTEM ARCHIVE LOG CURRENT, or
5. ALTER SYSTEM SWITCH LOGFILE
6. SELECT name, is_recovery_dest_file FROM v$archive_log

Commands to Perform a Hot Backup

1. ALTER TABLESPACE <name> BEGIN BACKUP
2. LIST BACKUP OF DATABASE
3. LIST BACKUP OF ARCHIVE ALL;
4. REPORT NEED BACKUP;
5. REPORTOBSOLETE

RMAN commands

All the RMAN command are listed at the bottom.

1. CROSSCHECK
2. DELETE EXPIRED
3. DELETE OBSOLETE
4. CATALOG

Copy the file(s) to the new location.

RMAN> COPY DATAFILE 8 TO '/u01/app/oracle/oradata/users.dbf';

Turn the tablespace to offline. We could have turned the tablespace offline before the copy, removing the need for a recovery, but the tablespace would have been offline longer using that method.

RMAN> SQL 'ALTER TABLESPACE USERS OFFLINE';

Switch to the new datafile copy(s) and recover the tablespace.

RMAN> SWITCH DATAFILE 8 TO COPY;
RMAN> RECOVER TABLESPACE users;

Turn the tablespace online again.

RMAN> SQL 'ALTER TABLESPACE users ONLINE';

Remove the old datafile(s).

RMAN> HOST 'rm /u01/app/oracle/product/11.2.0.3/dbs/users.dbf';

AUDITING

DB_DBA_AUDIT_TRAIL –>

Value Based Triggers

FGA_DBMS_FGA (all rows)         These two views combine to form DBA_COMMON_AUDIT_TRAIL

 DBA_FGA_AUDIT_TRAIL–>

ALERTS – Threshold Alerts – MMON – stateful

DBA_SERVER_ALERT

DBA_OUTSTANDING_ALERTS

DBA_ALERT_HISTORY –>   “snapshot too old is stateless”

 

STATISTICS

TABLEs                  DBA_TABLES

COLUMNS             DBA_TAB_COLUMNS

INDEXES               DBA_INDEXES, INDEX_STATS

 

STATISTICS_LEVEL = TYPICAL, ALL, BASIC

 

OPATCH

opatch apply

opatch rollback

 

To move or rename a datafile do the following.

• Shutdown the database.
• Rename the physical file on the OS.
• Start the database in mount mode.
• Issue the ALTER DATABASE RENAME FILE command to rename the file within the Oracle dictionary.
• Open the database.

To move or rename a controlfile do the following.

• Alter the control_files parameter using the ALTER SYSTEM comamnd.
• Shutdown the database.
• Rename the physical file on the OS.
• Start the database.

 RMAN Commands

Command	Purpose
“@”	Run a command file.
“@@”	Run a command file in the same directory as another command file that is currently running. The @@ command differs from the @ command only when run from within a command file.
“ALLOCATE CHANNEL”	Establish a channel, which is a connection between RMAN and a database instance.
“ALLOCATE CHANNEL FOR MAINTENANCE”	Allocate a channel in preparation for issuing maintenance commands such as DELETE.
“allocOperandList”	A subclause that specifies channel control options such as PARMS and FORMAT.
“ALTER DATABASE”	Mount or open a database.
“archivelogRecordSpecifier”	Specify a range of archived redo logs files.
“BACKUP”	Back up database files, copies of database files, archived logs, or backup sets.
“BLOCKRECOVER”	Recover an individual data block or set of data blocks within one or more datafiles.
“CATALOG”	Add information about a datafile copy, archived redo log, or control file copy to the repository.
“CHANGE”	Mark a backup piece, image copy, or archived redo log as having the status UNAVAILABLE or AVAILABLE; remove the repository record for a backup or copy; override the retention policy for a backup or copy.
“completedTimeSpec”	Specify a time range during which the backup or copy completed.
“CONFIGURE”	Configure persistent RMAN settings. These settings apply to all RMAN sessions until explicitly changed or disabled.
“CONNECT”	Establish a connection between RMAN and a target, auxiliary, or recovery catalog database.
“connectStringSpec”	Specify the username, password, and net service name for connecting to a target, recovery catalog, or auxiliary database. The connection is necessary to authenticate the user and identify the database.
“CONVERT”	Converts datafile formats for transporting tablespaces across platforms.
“CREATE CATALOG”	Create the schema for the recovery catalog.
“CREATE SCRIPT”	Create a stored script and store it in the recovery catalog.
“CROSSCHECK”	Determine whether files managed by RMAN, such as archived logs, datafile copies, and backup pieces, still exist on disk or tape.
“datafileSpec”	Specify a datafile by filename or absolute file number.
“DELETE”	Delete backups and copies, remove references to them from the recovery catalog, and update their control file records to status DELETED.
“DELETE SCRIPT”	Delete a stored script from the recovery catalog.
“deviceSpecifier”	Specify the type of storage device for a backup or copy.
“DROP CATALOG”	Remove the schema from the recovery catalog.
“DROP DATABASE”	Deletes the target database from disk and unregisters it.
“DUPLICATE”	Use backups of the target database to create a duplicate database that you can use for testing purposes or to create a standby database.
“EXECUTE SCRIPT”	Run an RMAN stored script.
“EXIT”	Quit the RMAN executable.
“fileNameConversionSpec”	Specify patterns to transform source to target filenames during BACKUP AS COPY, CONVERT and DUPLICATE.
“FLASHBACK”	Returns the database to its state at a previous time or SCN.
“formatSpec”	Specify a filename format for a backup or copy.
“HOST”	Invoke an operating system command-line subshell from within RMAN or run a specific operating system command.
“keepOption”	Specify that a backup or copy should or should not be exempt from the current retention policy.
“LIST”	Produce a detailed listing of backup sets or copies.
“listObjList”	A subclause used to specify which items will be displayed by the LIST command.
“maintQualifier”	A subclause used to specify additional options for maintenance commands such as DELETE and CHANGE.
“maintSpec”	A subclause used to specify the files operated on by maintenance commands such as CHANGE, CROSSCHECK, and DELETE.
“obsOperandList”	A subclause used to determine which backups and copies are obsolete.
“PRINT SCRIPT”	Display a stored script.
“QUIT”	Exit the RMAN executable.
“recordSpec”	A subclause used to specify which objects the maintenance commands should operate on.
“RECOVER”	Apply redo logs and incremental backups to datafiles restored from backup or datafile copies, in order to update them to a specified time.
“REGISTER”	Register the target database in the recovery catalog.
“RELEASE CHANNEL”	Release a channel that was allocated with an ALLOCATE CHANNEL command.
“releaseForMaint”	Release a channel allocated with an ALLOCATE CHANNEL FOR MAINTENANCE command.
“REPLACE SCRIPT”	Replace an existing script stored in the recovery catalog. If the script does not exist, then REPLACE SCRIPT creates it.
“REPORT”	Perform detailed analyses of the content of the recovery catalog.
“RESET DATABASE”	Inform RMAN that the SQL statement ALTER DATABASE OPEN RESETLOGS has been executed and that a new incarnation of the target database has been created, or reset the target database to a prior incarnation.
“RESTORE”	Restore files from backup sets or from disk copies to the default or a new location.
“RESYNC”	Perform a full resynchronization, which creates a snapshot control file and then copies any new or changed information from that snapshot control file to the recovery catalog.
“RUN”	Execute a sequence of one or more RMAN commands, which are one or more statements executed within the braces of RUN.
“SEND”	Send a vendor-specific quoted string to one or more specific channels.
“SET”	Sets the value of various attributes that affect RMAN behavior for the duration of a RUN block or a session.
“SHOW”	Displays the current CONFIGURE settings.
“SHUTDOWN”	Shut down the target database. This command is equivalent to the SQL*Plus SHUTDOWN command.
“SPOOL”	Write RMAN output to a log file.
“SQL”	Execute a SQL statement from within Recovery Manager.
“STARTUP”	Start up the target database. This command is equivalent to the SQL*Plus STARTUP command.
“SWITCH”	Specify that a datafile copy is now the current datafile, that is, the datafile pointed to by the control file. This command is equivalent to the SQL statement ALTER DATABASE RENAME FILE as it applies to datafiles.
“UNREGISTER DATABASE”	Unregisters a database from the recovery catalog.
“untilClause”	A subclause specifying an upper limit by time, SCN, or log sequence number. This clause is usually used to specify the desired point in time for an incomplete recovery.
“UPGRADE CATALOG”	Upgrade the recovery catalog schema from an older version to the version required by the RMAN executable.
“VALIDATE”	Examine a backup set and report whether its data is intact. RMAN scans all of the backup pieces in the specified backup sets and looks at the checksums to verify that the contents can be successfully restored.