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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An Extent is a specific number of contiguous data blocks, obtained in a single allocation, and used to store a specific type of information.

gaurav_varma

 Profile Answers by gaurav_varma Questions by gaurav_varma

• Jan 10th, 2007

An extent is a logical unit of database storage space allocation made up of a number of contiguous data blocks. One or more extents in turn make up a segment. When the existing space in a segment is c...

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A segment is a set of extents allocated for a certain logical structure.

gaurav_varma

 Profile Answers by gaurav_varma Questions by gaurav_varma

• Jan 10th, 2007

A segment is a set of extents that contains all the data for a specific logical storage structure within a tablespace. For example, for each table, Oracle allocates one or more extents to form that ta...

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Data Segment, Index Segment, Rollback Segment and Temporary Segment.

taraldesai

 Profile Answers by taraldesai Questions by taraldesai

• Jan 28th, 2008

Data, index , rollback, undo,cluster

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Each Index has an Index segment that stores all of its data.

taraldesai

 Profile Answers by taraldesai Questions by taraldesai

• Jan 28th, 2008

It's an oracle object as other object like table. It stores index key + rowid for that key. So when you scan index it finds respective rowid and fetch data from that rowid. and it's faster

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A Database contains one or more Rollback Segments to temporarily store "undo" information.

taraldesai

 Profile Answers by taraldesai Questions by taraldesai

• Jan 28th, 2008

It stores your uncommited temporart data. ex. If you do any insert/update/delete and you won't commit it is written in rollback segment.

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Here i'm sending all of you the error which occurred frequently during database connection.While creating a data block in Oracle Forms, the error which encountered frequently is "ORA-12560: TNS Protocol Adapter Error" During lectures instructor had told us that if such error encountered then copy the TNSNAMES.ORA file from ..oracleora92networkadminsample to forms9inetworkadminsample as it contains...

sahil4439

 Profile Answers by sahil4439 Questions by sahil4439

• Jun 15th, 2008

dude  ur databse is not running...right click on my compiuter>manage>services& applictaions(on right side)>services>oracle_databse_name(the datasbe  that ur  trying ...

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what is remote login user and local user in database?And sid is used when user want to login as local user and Glodal database name is used when user wants to login as remote user..What does it mean ?

cmanan

 Profile Answers by cmanan Questions by cmanan

• Jul 10th, 2008

When you have distributed environment,you may access one database from other.This is normally done  via db link.So lets say you have flight database and customer dabatabase.Now from customer data...

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Hi,

If a user executes a query which is already being used by a view exactly will oracle use already existing view to retrieve data or use the query executed by user?

Regards,
Shashi

Aayudh

• Aug 24th, 2011

Oracle uses query executed by user because when you use a view name in an other query, it simply transform query. select empid,name from emp; --- original create view emp_view as select empid,name f...

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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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