Beginning XML Databases (Wrox Beginning Guides)

1. 

VLDB stands for ______ ______ _________.

2. 

OLTP stands for _____ ____________ __________.

3. 

NXD stands for ________ ___ ________.

4. 

Pick the best answer:

1. The typical size of a modern-day VLDB is megabytes, and NXD is gigabytes.

2. The typical size of a modern-day VLDB is gigabytes, and NXD is megabytes.

3. The typical size of a modern-day VLDB is gigabytes, and NXD is gigabytes.

4. The typical size of a modern-day VLDB is terabytes, and NXD is megabytes.

5. None of the above.

5. 

XML data improves on relational data in which of the following ways?

1. Flattened XML documents contain data and metadata describing data directly.

2. Hierarchical XML documents contain data, metadata, and relationships between different data items.

3. Both of the above.

4. Neither of the above.

6. 

Which of these is true?

1. Schema-dependent XML document collections can be validated and can have good data integrity.

2. Schema-less XML document collections are extremely flexible but lack data integrity validation.

3. XML document collection elements can each be complete XML documents or XML fragments .

4. XML document collections can have varying content and structure within the same collection.

5. All of the above.

6. None of the above.

7. 

Typical XML indexes are of which of the following forms?

1. Structural indexes based on XML document hierarchical structure and node placement within that structure.

2. Value indexes comprised of the text values of nodes and the values of attributes.

3. Concurrency indexes made up of multi- user XML document attributes.

4. Transactional indexes created when XML data is created and terminated when XML data is destroyed .

5. None of the above.

1.  

Exercise 1 solution

Very Large Database

2.  

Exercise 2 solution

Online Transaction Processing

3.  

Exercise 3 solution

Native XML Database

4.  

Exercise 4 solution

d. The typical sizes of a modern day VLDB is terabytes and NXD is megabytes. This answer is correct for both data warehouses, as well as for some very large OLTP databases. Native XML databases are not implemented beyond megabyte sizes.

5.  

Exercise 5 solution

c. Both of the above. Both a and b are correct. Flattened XML documents contain only a root level and a single layer underneath. Hierarchical XML documents contain multiple hierarchical layers , describing structure with respect to relationships between different classes and types of metadata.

6.  

Exercise 6 solution

e. All of the above. XML documents and XML fragments can be stored in native XML databases as collections. Those collections can be validated against schemas, or not. Schemas increase data integrity but reduce flexibility. Not using schemas for collections allows fragments to differ both structurally and on content.

7.  

Exercise 7 solution

a and b are both correct. c is just completely silly because concurrency has little to do with indexing in this case. d is even more ridiculous because there is no such thing as a transactional index, in any database, and creation and destruction of XML data may be transactional but have nothing to do with a non-existent index type.