Your Answer : (Not Answered)

Correct Answer : D

Correct answer: All of the above.

Location transparency means nobody has to know where the data physically sits - not the user writing a query, not the programmer writing an application, not the manager reading a report. The system resolves the location, which is what allows data to be moved between sites without changing anything above.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: May transmit message packets to the correct destination.

Forwarding packets to their destination is the work of a router. An intrusion detection system watches rather than forwards: it inspects traffic for signs of attack, looks for known attack signatures, and may run deception systems to draw an intruder into a monitored area.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: True

The database server does all three: it stores the data, controls access to it, and performs the processing needed to answer a query - selecting, joining, aggregating - so that only the result crosses the network. That last point is what separates it from a file server, which ships whole files and leaves the work to the client.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: two-dimensional tables.

A relation has exactly two dimensions: rows, which are the tuples, and columns, which are the attributes. Everything else - hierarchies, time series, multidimensional analysis - must be expressed within that structure, which is both the model’s limitation and the source of its simplicity.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: One relation is created.

A regular entity maps directly to a single relation: its identifier becomes the primary key and its simple attributes become columns. Composite attributes contribute their components, and multivalued attributes are the exception, requiring a relation of their own.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: First normal form

First normal form is defined by every attribute being single-valued, so removing the multivalued attributes achieves it and nothing more. Partial and transitive dependencies may still be present, and removing those is what the higher forms are for.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

A supertype ordinarily has several subtypes, since the point of the construct is to distinguish kinds. A single subtype is possible but unusual and generally means the modeller has found an exception rather than a genuine classification.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

A workgroup is small - conventionally fewer than 25 people - and is defined by working together on a common task rather than by any particular size. The range of 25 to 100 belongs to a departmental database, the next level up in the usual classification.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: program-data dependency.

Program-data independence is the advantage - the descriptions live in the catalogue rather than in each program, so a change to the data does not require every program to be rewritten. Dependence is the file-processing defect that the database approach exists to remove, so it is the odd one out here.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: True

This is what the virtual machine is for. The compiler produces bytecode, which no processor can execute, and the JVM reads and executes it at run time. Modern implementations compile hot paths to native code as they run, but the essential arrangement is unchanged: the bytecode is portable and the JVM is what makes it executable.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: DDL

CREATE TABLE defines a new relation, naming its attributes and their domains, so it is a Data Definition Language statement.

The test is what the statement acts on: DDL changes the structure of the database, DML changes the data within it. Nothing is stored by this statement - it produces an empty table awaiting rows. The declaration name varchar is worth noticing as incomplete in standard SQL, which requires a length as varchar(n).

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

Properties and methods belong to the object model. A schema consists of elements and attributes, together with the types and occurrence constraints that govern them. The vocabulary follows the document view of data rather than the object one, which is worth keeping straight when moving between the two worlds.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

The first half is right and the second is wrong. ADO does overlie the more complex OLE DB model, and that is its purpose - but it is callable from programming languages as well as scripting ones, from Visual Basic and C++ as readily as from VBScript. Being usable from almost any language able to work with COM is exactly what ADO was created for.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

This describes the driver, not the driver manager. The driver is the DBMS-specific component that turns ODBC requests into statements the particular data source understands. The driver manager’s job is to decide which driver a named data source requires, load it, and pass the calls through to it.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

No database stays correct, because the organisation it serves does not stay still. New requirements, new regulations, new products and mergers all change what the data must represent, so redesign follows from changed needs rather than from original error. Building it well the first time makes redesign easier, not unnecessary.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: False

Referential integrity requires only that a non-null foreign key match an existing primary key value. A NULL is permitted and simply means the relationship is unknown or does not apply, unless the column is separately declared NOT NULL.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: Driver

The driver is the DBMS-specific component: it receives an ODBC request and translates it into statements the particular data source understands, then translates the results back. The driver manager sits above it and chooses which driver to load, and the data source names the database and the DBMS that processes it.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: database has no data.

With no data present, changing the structure is simply a matter of issuing the DDL: there is nothing to convert, nothing to lose and no constraint that existing rows might violate. Every real difficulty in redesign comes from the data - values that will not fit the new type, rows that break a new constraint, relationships whose cardinality the existing rows do not satisfy. Size and quality of design affect the work, but neither removes it.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Tuple.

In relational terminology a row is a tuple, a column is an attribute, the table itself is a relation, the number of attributes is its degree and the number of tuples its cardinality.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: True

XML matters in database processing as the standard way of moving structured data between systems that share no common database: web services, business-to-business exchange, configuration and document storage. Most DBMS products now store and query XML directly, and the family of related standards - XPath, XSLT, XML Schema - goes with it.