The Information in a redo log file is used only to recover the database from a system or media failure prevents database data from being written to a database's data files.

Dinesh Chandra

• Aug 27th, 2012

Redo log records the changes made in database. Redo logs is mainly used to recover data.

rohitmisri

 Profile Answers by rohitmisri Questions by rohitmisri

• Jun 17th, 2010

Hi,Redo log information is the one of the major pard of the database , at any time if the oracle server instance get aborted and then it need recovery, so at that time redo log plays a role to recover...

Answer Question  Select Best Answer

A schema is collection of database objects of a User.

ARUN BHUKKER

 Profile Answers by ARUN BHUKKER Questions by ARUN BHUKKER

• Oct 19th, 2012

A schema is the set of objects (tables, views, indexes, etc) that belongs to an user account. It is often used as another way to refer to an Oracle account. Most Oracle database installations traditio...

Mohammad Mujeeb

• Oct 25th, 2011

Schema is a collect of object (table,view,cluster etc) that belongs to an user account.

Answer Question  Select Best Answer

Where does the process dumps information about the error?

ARUN BHUKKER

 Profile Answers by ARUN BHUKKER Questions by ARUN BHUKKER

• Oct 19th, 2012

Errors are stored in alert.log file it can be shecked using the parameter background_dump_dest

Use show parameter background_dump_dest
for path of the alert.log in trace directory

matabrez

 Profile Answers by matabrez Questions by matabrez

• Jan 10th, 2011

Alerts will log to alert.log  and alert trace files will be saved in  $ORACLE_HOME/admin/bdump directory.

Answer Question  Select Best Answer

What is the use of archive log file? How will you apply archive log file? How does archive log file helps to make backup consistent?

ARUN BHUKKER

 Profile Answers by ARUN BHUKKER Questions by ARUN BHUKKER

• Oct 19th, 2012

A Archive log file is used to archive the filled redo log files. and used in recovery.

It is used in recovery but not in instance recovery.
Rest it is used to make database consistent after recovery by matching header of data file and control file checkpoint information.

rsona

 Profile Answers by rsona Questions by rsona

• Mar 2nd, 2011

Hello Ganesh,Q : What is the use of archive log file? A : It is used for Point In Time Database Instance Recovery.     Q : How will you apply archive log file? A : Archive Log need...

Answer Question  Select Best Answer

sandeep

• Apr 26th, 2013

Ps -ef | grep oracle

chittu.kotian

 Profile Answers by chittu.kotian Questions by chittu.kotian

• May 16th, 2012

On Unix the command is ps -aef | grep -i pmon

Answer Question  Select Best Answer

How we can determine the physical architecture of oracle?

ranjithsv

• Oct 2nd, 2013

Datafiles(*.dbf),
Controlfiles(*.ctl),
Redologfiles(*.log),
Archivelogfiles(*.arc)

ARUN BHUKKER

 Profile Answers by ARUN BHUKKER Questions by ARUN BHUKKER

• Oct 19th, 2012

Oracle architecture consist of four structures: 1. Memory structure (SGA, PGA) 2. Process structure (user process, server process, background process) 3. Physical structure (data files, redo log files...

Answer Question  Select Best Answer

How does the SMON process performs recovery after instance failure?

ranjithsv18

• Oct 2nd, 2013

When hardware failure, software failue and shutdown abnormally happen... SMON taking care of Instance failure, coalesce failure space and deallocating temp segment start to recover instance Roll fw...

Nagaraj OCP

• Dec 27th, 2011

When shutdown abort happens, oracle server gets crashed. To recover from the crash, SMON will check the online Redo data files and last SCN no in the Redo log files and SCN number in the undo tablespa...

Answer Question  Select Best Answer

ranjithsv

• Oct 2nd, 2013

Its relation between SGA and 5 Mandatory Background process
SMON,PMON,DBWR,LGWR,CKPT

ARUN BHUKKER

 Profile Answers by ARUN BHUKKER Questions by ARUN BHUKKER

• Oct 19th, 2012

A background process maintain relationship between memory structure and physical structure of Oracle server. Started when Oracle instance is started. Consist of 5 mandatory and some optional backgro...

Answer Question  Select Best Answer

A data file can be associated with only one database. Once created a data file can't change size.One or more data files form a logical unit of database storage called a tablespace.

ranjithsv18

• Oct 2nd, 2013

Block size available from 2k,4k,8k,16k and 32k.

As per oracle point of view Default (or) standard block size is 8k for Data files.The initialization parameter

db_block_size=8k (8192)remaining size are non-standard blok size. Extents size 64k.

(Datafile

NAGARAJ OCP

• Dec 27th, 2011

In data files, we cant change the extent management, type of it. But we can change the storage space for it if we need after the database (tablespace) creation.

Answer Question  Select Best Answer

Harshad Khuspe

• Feb 26th, 2015

Virtual Tables are contains information about the base tables in oracle. Like V$database is virtual table which provide information of database name, open mode etc. or v$log will provide redo log members etc.

ARUN BHUKKER

 Profile Answers by ARUN BHUKKER Questions by ARUN BHUKKER

• Oct 19th, 2012

Either virtual table is a temporary table or v$ or Xv$ views

Answer Question  Select Best Answer

A database link is a named object that describes a "path" from one database to another.

Vinod Karuturi

• Nov 16th, 2015

A database link is a schema object in one database that enables you to access objects on another database. The other database need not be an Oracle Database system. However, to access non-Oracle systems you must use Oracle Heterogeneous Services.

Madhu Alampalli

• Sep 24th, 2015

Cluster key is a related column of tables in the cluster. For example, in Table EMP which has (EMP NO, EMP NAME, DEP NO, etc ) and DEPT which has (DEPT NAME, DEPT NO etc), DEPT NO is the cluster key in this cluster.

Answer Question  Select Best Answer

Yes.

mayur

• Dec 24th, 2015

No, at a time only one tablespace as default can be allocate to any user. If we want to store objects of one user to multiple tablespace then assign that tablespaces as a default tablespace for user at a time

matabrez

 Profile Answers by matabrez Questions by matabrez

• Jan 10th, 2011

Yes objects of the same schema can reside in different tablepaces. Becuase when we create any schema (user) we can assign many tablespaces to one shcema so objects (eg. tables) will create in different tablespaces.

Answer Question  Select Best Answer

What are the advantages & disadvantages of both two.

Harshad Khuspe

• Dec 27th, 2015

In case of RAC (Real Application Cluster) use of GNS will be helpful if we have more than 10 node cluster. GNS need not to be assign IP addresses and it select automatically with the help of DHCP

frankie Lester

• Aug 11th, 2015

GNS uses DNS and DHCP to assign IP address on the network.

Answer Question  Select Best Answer

Each Non-clustered table has a data segment. All of the table's data is stored in the extents of its data segment. Each cluster has a data segment. The data of every table in the cluster is stored in the cluster's data segment.

Harshad Khuspe

• Dec 27th, 2015

Tablespace is made up of Segment. Segment is made up of extents and extents are made up of contiguous oracle blocks. Segments are nothing but a table. i.e. Table Emp is nothing but segment emp. You can check things from data dictionary view DBA_Segments.

pradeep

• May 5th, 2015

A data segment is a set of extents allocated to a certain logical structures

Answer Question  Select Best Answer

Sarkar

• Mar 29th, 2016

I want to know about wrap background logic.

akebono

 Profile Answers by akebono Questions by akebono

• Jan 30th, 2009

DBMS_OBFUSCATION_TOOLKIT package is  a simple API for data encryption

Answer Question  Select Best Answer

What is the difference between log sequence number and checkpoint id? How it is used for instance recovery?

vishal gajage

• Jun 21st, 2017

Log Sequence Number is assigned to every redo log file after full the redo log file....and SCN number is generated after every commit

aditya verma

• May 11th, 2017

Logs sequence no is the value which is mention in header of every datafile. Below is the situations when SCN changed.
After every commit the transaction.
Log switch.
Backup completion.

Answer Question  Select Best Answer

SID (System Identifier)  :  A SID (almost) uniquely identifies an instance.  Actually, $ORACLE_HOME, $ORACLE_SID and $HOSTNAME identify an instance uniquely. The SID is 64 characters, or less; at least on Oracle 9i. The system identifier is included in the CONNECT_DATA parts of the connect descriptors in a tnsnames.ora file. The SID defaults to the database name. Global Database Name...

pavan

• Jul 4th, 2017

Can a database name can be same across multiple instances, and can the instances number be same? If yes what is SID in that case?

shaikhannan

 Profile Answers by shaikhannan Questions by shaikhannan

• Feb 3rd, 2010

SID = identifies the database instance (database name + instance number). So if your database name is somedb and your instance number is 3, then your SID is somedb3. DB Name = Name of the database (d...

Answer Question  Select Best Answer

Heena

• Sep 17th, 2017

Database writer process(DBWn)

sriram

• May 17th, 2016

DBWR is one of the BG processed of Oracle DB. It writes modifies the data in data base buffer cache

Answer Question  Select Best Answer

Prabhat Sahu

• Oct 21st, 2017

B-Tree Index:
1. Oracle Default index.
2. Cardinality is High, means less duplicate(more unique records) (i.e. Rowid)

Bitmap Index:
1. Cardinality is Low, means more duplicate.(most of the values are repetative)
2. Flag related columns ( i.e. M/F, Y/N, 1/0 )

Vineet

• Oct 12th, 2017

1. B-tree Index has high cardinality values, where as Bitmap Index has low Cardinality values.

Answer Question  Select Best Answer

When does the LGWR writes all redo-enteries to the redo-log buffer?

Suresh

• Oct 31st, 2017

1) When user hits commit
2) When there is 1/3rd full in redo log cache
3) One every 3 seconds

During this above situation LGWR writes redo log entries into redo log files from redo log cache !!

Mayur Pimpalkar

• Dec 24th, 2015

Lwgr process writes redo entries to online redolog files not to redobuffer.

Answer Question  Select Best Answer