67. What are the unary operations in Relational Algebra? PROJECTION and SELECTION. 68. Are the resulting relations of PRODUCT and […]
61. What do you mean by flat file database? It is a database in which there are no programs or
55. What is meant by query optimization? The phase that identifies an efficient execution plan for evaluating a query that
49. What is 4NF? A relation schema R is said to be in 4NF if for every Multivalued dependency X
43. What is Lossless join property? It guarantees that the spurious tuple generation does not occur with respect to relation
37. What is Set-at-a-time or Set-oriented? The High level or Non-procedural DML can specify and retrieve many records in a
31. What is Data Storage – Definition Language? The storage structures and access methods used by database system are specified
25. What is Relationship set? The collection (or set) of similar relationships. 26. What is Relationship type? Relationship type defines
19. What is an Extension of entity type? The collections of entities of a particular entity type are grouped together
1. What is database? A database is a logically coherent collection of data with some inherent meaning, representing some aspect
13. What is Data Model? A collection of conceptual tools for describing data, data relationships data semantics and constraints. 14.
7. Define the “integrity rules”? There are two Integrity rules. Entity Integrity: States that “Primary key cannot have NULL value”
1. What is database? A database is a logically coherent collection of data with some inherent meaning, representing some aspect
181. What method must be implemented by all threads? All tasks must implement the run() method, whether they are a
175. What is a Java package and how is it used? A Java package is a naming context for classes
169. What is the difference between a Scrollbar and a ScrollPane? A Scrollbar is a Component, but not a Container.
163. Which arithmetic operations can result in the throwing of an ArithmeticException? Integer / and % can result in the
157. What is a compilation unit? A compilation unit is a Java source code file. 158. What interface is extended
151. What is the difference between the File and RandomAccessFile classes? The File class encapsulates the files and directories of
45. What is the Set interface? The Set interface provides methods for accessing the elements of a finite mathematical set.
139. What Checkbox method allows you to tell if a Checkbox is checked? getState(). 140. What state is a thread
133. What is the difference between a field variable and a local variable? A field variable is a variable that
127. What is casting? There are two types of casting, casting between primitive numeric types and casting between object references.
121. Which class is the immediate superclass of the Container class? Component. 122. If a method is declared as protected,
115. What is the purpose of the File class? The File class is used to create objects that provide access
