Advanced Databases

The total participation by entities is represented in E-R diagram as?

• Dashed Line

• Double Line

• Double Rectangle

• Circle

Answer explanation

In an E-R diagram, total participation of entities is indicated by a double line. This signifies that every instance of the entity must participate in the relationship, distinguishing it from partial participation, which uses a single line.

A relationship is?

• An item in an application

• A collection of related entities

• Related data

• A meaningful dependency between entities

Answer explanation

A relationship is best defined as a meaningful dependency between entities, as it captures how different entities interact and rely on each other, making this choice the most accurate among the options.

A _________ consists of a sequence of query and/or update statements

• transaction

• commit

• rollback

• flashback

Answer explanation

A transaction consists of a sequence of query and/or update statements that are executed as a single unit. This ensures data integrity, making 'transaction' the correct choice over 'commit', 'rollback', or 'flashback'.

Which of the following is another name for weak entity?

• child

• dominat

• owner

• all of these

Answer explanation

A weak entity is often referred to as a 'child' entity because it depends on a 'parent' or 'owner' entity for its existence. Therefore, 'child' is the correct answer, while 'dominat' and 'owner' are not standard terms for weak entities.

According to enhanced-entity relationships, association between super class and subclass is

• Super class is subset of subclass

• Subclass is subset of subclass

• Subclass is partial joint of super class

• Super class is partial joint of subclass

Answer explanation

In enhanced-entity relationships, a subclass represents a specific subset of the superclass. Therefore, the correct choice is that the subclass is a subset of the superclass, not the other way around.

Which of the following is not a PL/SQL identifier?

• cursors

• tuples

• exceptions

• constants

Answer explanation

In PL/SQL, 'tuples' is not a recognized identifier. Cursors, exceptions, and constants are valid identifiers used in PL/SQL programming, while tuples are more commonly associated with data structures in other programming languages.

Which join refers to join records from the right table that have no matching key in the left table are include in the result set?

• Left outer join

• Right outer join

• Full outer join

• Half join

Answer explanation

The right outer join includes all records from the right table, even if there are no matching keys in the left table. This is why the correct answer is 'Right outer join', as it specifically addresses the scenario described.

_______________ is a procedural extension of Oracle – SQL that offers language constructs similar to those in imperative programming languages

• SQL

• PL/SQL

• Advanced SQL

• PQL

Answer explanation

PL/SQL is the correct answer as it is a procedural extension of Oracle SQL, incorporating features from imperative programming languages, allowing for more complex programming constructs compared to standard SQL.

A trigger can be dropped by using command

• Alter trigger drop

• Define trigger drop

• Drop trigger

• Declare drop trigger

Answer explanation

The correct command to drop a trigger in SQL is 'Drop trigger'. The other options are incorrect syntax and do not represent valid SQL commands for this action.

Which of the following is not a grouping function?

• COUNT

• SUM

• DISTINCT

• MIN

Answer explanation

DISTINCT is not a grouping function; it is used to return unique values from a dataset. In contrast, COUNT, SUM, and MIN are all functions that aggregate data, making them true grouping functions.