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Recent Questions

Davinder Singh - 4 years ago in Database Management System
The term Complete for a UML has the same meaning as which of the following for an EER diagram?
  • [A] Overlapping rule
  • [B] Disjoint rule
  • [C] Total specialization rule
  • [D] Partial specialization rule
Davinder Singh - 4 years ago in Database Management System
An abstract class is which of the following?
  • [A] A class that has direct instances, but whose descendants may have direct instances.
  • [B] A class that has no direct instances, but whose descendants may have direct instances.
  • [C] A class that has direct instances, but whose descendants may not have direct instances.
  • [D] A class that has no direct instances, but whose descendants may not have direct instances
Davinder Singh - 4 years ago in Database Management System
Composition is a stronger form of which of the following?
  • [A] Aggregation
  • [B] Encapsulation
  • [C] Inheritance
  • [D] All of the above.
Davinder Singh - 4 years ago in Database Management System
The fact that the same operation may apply to two or more classes is called what?
  • [A] Inheritance
  • [B] Polymorphism
  • [C] Encapsulation
  • [D] Multiple classification
Davinder Singh - 4 years ago in Database Management System
A tool that can help designers understand the dependencies of database structures is a:
  • [A] dependency graph.
  • [B] data model.
  • [C] graphical display.
  • [D] None of the above is correct.
Davinder Singh - 4 years ago in Database Management System
Which is not true of a correlated subquery?
  • [A] EXISTS/NOT EXISTS is a form of a correlated subquery.
  • [B] The processing of the SELECT statements is nested.
  • [C] They can be used to verify functional dependencies.
  • [D] They are very similar to a regular subquery.
Davinder Singh - 4 years ago in Database Management System
What SQL command will allow you to change the table STUDENT to add the constraint named GradeCheck that states that the values of the Grade column must be greater than 0?
  • [A] ALTER TABLE STUDENT ALTER CONSTRAINT GradeCheck (Grade > 0);
  • [B] ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck (Grade > 0);
  • [C] ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck CHECK (Grade > 0);
  • [D] None of the above is correct.
Davinder Singh - 4 years ago in Database Management System
To drop a column that is used as a foreign key, first:
  • [A] drop the primary key.
  • [B] drop the table containing the foreign key..
  • [C] drop the foreign key constraint.
  • [D] All of the above must be done.
Davinder Singh - 4 years ago in Database Management System
The data model that is produced from reverse engineering is:
  • [A] a conceptual model.
  • [B] an internal model.
  • [C] a logical model.
  • [D] None of the above is correct.
Davinder Singh - 4 years ago in Database Management System
Changing cardinalities in a database is:
  • [A] a common database design task.
  • [B] a rare database design task, but does occur.
  • [C] a database design task that never occurs.
  • [D] is impossible to do, so a new database must be constructed and the data moved into it.
Davinder Singh - 4 years ago in Database Management System
The EXISTS keyword will be true if:
  • [A] any row in the subquery meets the condition only.
  • [B] all rows in the subquery fail the condition only.
  • [C] both of these two conditions are met.
  • [D] neither of these two conditions is met.
Davinder Singh - 4 years ago in Database Management System
Which of the following modifications may not succeed?
  • [A] Changing a column data type from char to date
  • [B] Changing a column data type from numeric to char
  • [C] Both of the above actions should succeed.
  • [D] Neither of the above actions will succeed.
Davinder Singh - 4 years ago in Database Management System
Before any changes to database structure are attempted one should first:
  • [A] clearly understand the current structure and contents of the database only.
  • [B] test any changes on a test database only.
  • [C] create a complete backup of the operational database only.
  • [D] All of the above should be done.
Davinder Singh - 4 years ago in Database Management System
The process of reading a database schema and producing a data model from that schema is known as:
  • [A] data modeling.
  • [B] database design.
  • [C] reverse engineering.
  • [D] None of the above is correct.
Davinder Singh - 4 years ago in Database Management System
Which SQL-92 standard SQL command can be used to change a table name?
  • [A] RENAME TABLE
  • [B] CHANGE TABLE
  • [C] ALTER TABLE
  • [D] None of the above is correct.
Davinder Singh - 4 years ago in Database Management System
Database redesign is not terribly difficult if the:
  • [A] database is structured.
  • [B] database is well-designed.
  • [C] database has no data.
  • [D] database is relatively small.
Davinder Singh - 4 years ago in Database Management System
What SQL command can be used to delete columns from a table?
  • [A] MODIFY TABLE TableName DROP COLUMN ColumnName
  • [B] MODIFY TABLE TableName DROP ColumnName
  • [C] ALTER TABLE TableName DROP COLUMN ColumnName
  • [D] ALTER TABLE TableName DROP ColumnName
Davinder Singh - 4 years ago in Database Management System
Which of the following SQL statements are helpful in database redesign?
  • [A] Correlated subqueries only
  • [B] EXISTS/NOT EXISTS expressions only
  • [C] Both of the above are helpful
  • [D] None of the above are helpful.
Davinder Singh - 4 years ago in Database Management System
SQL stands for ________ .
  • [A] Structured Question Language
  • [B] Structured Query Language
  • [C] Sequential Question Language
  • [D] Sequential Query Language