Set - 7

Question 81 :

What is a Synonym ?

Answer :

A synonym is an alias for a table, view, sequence or program unit.


Question 82 :

What is a Sequence ?

Answer :

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


Question 83 :

What is a Segment ?

Answer :

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


Question 84 :

What is schema?

Answer :

A schema is collection of database objects of a User.


Question 85 :

Describe Referential Integrity ?

Answer :

A rule defined on a column (or set of columns) in one table that allows the insert or update of a row only if the value for the column or set of columns (the dependent value) matches a value in a column of a related table (the referenced value). It also specifies the type of data manipulation allowed on referenced data and the action to be performed on dependent data as a result of any action on referenced data.