A materialized view is a replica of a target master from a singlepoint in time. The concept was first introduced with Oracle7 termed asSNAPSHOT. In Oracle release 7.1.6 snapshots were enhanced to enableDMLs along with a new terminology, updatable snapshots. With Oracle8.1.6 snapshots started to be used in data warehouse environments so anew terminology materialized view was introduced to address bothdistributed...

irfanyell

 Profile Answers by irfanyell Questions by irfanyell

• Apr 24th, 2008

Both are mirror copy of tables but in that main difference is in snapshot we cannot edit the data. in the case of materialized view we can edit the data.

pravin Karde

• Sep 25th, 2006

sir  i m a M.E. student & i developed a project on Materialized view selection & maintenance.sir for this i urgently need the architecture of Materialized view & its operation. sir pl. help me & send me if  possible.thanks waiting +vely.

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From where does PMON gets the informance about failure? How is the user process terminited?

premk

 Profile Answers by premk Questions by premk

• Dec 23rd, 2009

When user process is terminated abruptly due to power cut or any other factors then oracle database instance goes down then PMON mandatory background process is activated i.e it will then writes the c...

aabishkar

 Profile Answers by aabishkar Questions by aabishkar

• Sep 28th, 2009

When a user process fails or when it is killed, it then cleans up the cache and frees resources that the process used. PMON checks server processes and restarts them if they have failed.

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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...

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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

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The Primary function of the redo log is to record all changes made to data.

satyam_Ora

 Profile Answers by satyam_Ora Questions by satyam_Ora

• May 21st, 2008

Oracle maintains logs of all transactions against the databse. These transactions are recorded in files called Online Redo log files.These logs are used to recover the database's transaction in their ...

sujeshm

 Profile Answers by sujeshm Questions by sujeshm

• Feb 27th, 2006

Redo log is a part of physical structure of oracle. its basic function is to record all the changesmade to daatabase information. wheneveer an abnormal shutdown take place preventing system to update the database, changes can be obtained from redolog and hence the changes are not lost.

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No.

Tauseef

• Nov 25th, 2007

Yes. you can add integrity constraint. but that will effects the new records only not the existing one

Samuel Kiarie

• Mar 31st, 2006

Yes.Use Enable Novalidate to enforce the constraints. Existing data will not be checked, only new/update will be validated.

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A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can't contain Nulls.

soorajsk_84

 Profile Answers by soorajsk_84 Questions by soorajsk_84

• Aug 9th, 2007

A table can have any number unique keys but a single primary key

Thriveni P

• Mar 14th, 2006

A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can't contain Nulls.Unique key cannot be used to create referential integrity whereas primary key can do.

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A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.

Mohammed Abdul Afroze

• Sep 20th, 2007

It is a Logical area of storage in a Database, that directly corresponds to one or more physical files.

sandeep vig

• Oct 13th, 2005

A tablespace is a group of segments and a segment is a group of extents and an extent is a group of blocks.a tablespace can occupy two physical datafiles.

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Every ORACLE database contains a tablespace named SYSTEM, which is automatically created when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database.

Mohammed Abdul Afroze

• Sep 20th, 2007

Every Oracle Database contains a tablespace called system tablespace.This tablespace gets created at the time of database creation and it holds data dictionary information for the entire database.

Praveen

• Sep 15th, 2006

HelloAs far as i know, a system tablespace is the only tablespace which is created automatically, when the oracle DB is installed, no matter what the DB will contain atleast one tablespace and that  is the system tablespace. Do let me know if u have any other answers.Praveen.R

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A table is the basic unit of data storage in an ORACLE database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.

pravesh28

 Profile Answers by pravesh28 Questions by pravesh28

• Mar 27th, 2010

Table is manager which contain row and colomnin which store data ande retrive data

thumatinagaraju

 Profile Answers by thumatinagaraju Questions by thumatinagaraju

• Oct 24th, 2006

Table is data base object which stores the data in the logical representatiom in form of rows n coluns which is existing in two dimension form... and is stored in the databse.

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An integrity constraint is a declarative way to define a business rule for a column of a table.

simakas

• Oct 5th, 2007

Special requirements for table data:1) allow NULL value2) uniqueness of value3) primary key4) foreign key5) special value size/text/length etc requirementsAll information is stored in Data Dictionary.

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UPDATE and DELETE Restrict - A referential integrity rule that disallows the update or deletion of referenced data.DELETE Cascade - When a referenced row is deleted all associated dependent rows are deleted.

bahwesh

• Jul 17th, 2007

Foreign key value must exist as PK value on?some other ?table...FK?value can be null but?PK can't

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No Limit.

jjvetri

 Profile Answers by jjvetri Questions by jjvetri

• Aug 5th, 2009

You can create any number of check constraintsseparated by AND, OR, or NOT to create more complex conditions.

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Yes.

matabrez

 Profile Answers by matabrez Questions by matabrez

• Jan 10th, 2011

Yes one tablespace can hold objects from different schemas.Eg. when we create any schema (user) than we can assign default tablespace like this for any user user we can use same tablespace. Eg. SYSTE...

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Views do not contain or store data.

sanjay Pramanaik

• Oct 5th, 2006

?Hi,?? It? depends on the type of view it is.? if it is a normal view than it does not contains the data. and if it is materialsed view than it contains the data.?Thanks sanjay pramanik

kehri_anurag

 Profile Answers by kehri_anurag Questions by kehri_anurag

• Jan 13th, 2006

No, View never contain the the data, Only defination of it stores in the data base, when ever you invoke them they show you the data based on their defination.Only Materlized view or SnaptShot contain the the data.

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A sequence generates a serial list of unique numbers for numerical columns of a database's tables.

thumatinagaraju

 Profile Answers by thumatinagaraju Questions by thumatinagaraju

• Oct 24th, 2006

Nice answer soumyanag thumati_nagaraju@yahoo.co.in

soumya

• Jun 28th, 2006

A sequence is an automatically generated unique number.It is typically used to create a primary key value.It is a sharable object.Using sequence change the increment value, maximum value, minimum value, cycle option, or cache option.

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Synonyms are used to : Mask the real name and owner of an object.Provide public access to an objectProvide location transparency for tables, views or program units of a remote database.Simplify the SQL statements for database users.

harrykhokhar

 Profile Answers by harrykhokhar Questions by harrykhokhar

• Jun 1st, 2010

Synonyms are alternative names for the objects like views, indexes, etc.

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Indexes are automatically maintained and used by ORACLE. Changes to table data are automatically incorporated into all relevant indexes.

C.Ramesh

• Oct 18th, 2007

Index is a Database object . It can be accessed rows physical fast. when you move the table from different table spaces or same table spaces indexes will unusually status. So You compulsory rebuild the index. Rebuilding the index is very fast than drop and create the new indexes.

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Public database link is created for the special user group PUBLIC. A public database link can be used when any user in the associated database specifies a global object name in a SQL statement or object definition.

edeed

 Profile Answers by edeed Questions by edeed

• Mar 27th, 2008

A database link is a pointer that defines a one-way communication path from an Oracle Database server to another database server. The link pointer is actually defined as an entry in a data dictionary ...

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A data block size is specified for each ORACLE database when the database is created. A database users and allocated free database space in ORACLE datablocks. Block size is specified in INIT.ORA file and can’t be changed latter.

Sumer

 Profile Answers by Sumer Questions by Sumer

• Jan 5th, 2006

stansard block size, which is set with parameter DB_BLOCK_SIZE cannot be changed after creating database. We can set non standard parameter size later with parameter DB_nk_BLOCK_SIZE and it can be changed.NOTE: Standard block size cnannot be equal to nonstandars block size.

NARENDER REDDY

• Jan 4th, 2006

It can be changed later also by setting block_size in init.ora like 2 or 4 or 8 or 16. this feature available from oracle 9i. it can support multi block size.

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