MC	Which statement is CORRECT?	Document stores require users to define document schemas before data can be inserted.	incorrect	Redundancy is achieved through storing duplicate key-value pairs across multiple nodes.	correct	Column oriented databases are more efficient when inserts are performed where all of the row data is supplied at the same time.	incorrect	Horizontal scaling works best in an RDBMS.	incorrect	
MC	What does the following Cypher query express?<br><br>OPTIONAL MATCH (user;User)-[:FRIENDS_WITH]-(friend;User)<br>WHERE user.name = "Bart Baesens"<br>RETURN user, count(friend) AS NumberOfFriends	Get the node for Bart Baesens and a count of all his friends, even if no FRIENDS_WITH relation exists.	incorrect	Get the node for Bart Baesens and all his friends.	incorrect	This query will fail if Bart Baesens is FRIENDS_WITH himself.	incorrect	Get the node for Bart Baesens and a count of all his friends, but only if at least one FRIENDS_WITH relation exists.	correct	
MC	Which statement is CORRECT?	Document stores require that you perform all filtering and aggregation logic in your application.	incorrect	Document stores require users to define document schemas before data can be inserted.	incorrect	Document stores are built on the same ideas as key-value and tuple based database systems.	correct	Document stores do not provide SQL-like capabilities.	incorrect	
MC	Which statement is CORRECT?	Memcached provides data redundancy.	incorrect	The Memcached hash table can grow very large (several gigabytes), but is very difficult to scale across multiple servers.	incorrect	Memcached functions as a persistent database.	incorrect	When using Memcached, it is the client's responsibility to distribute data entries among the different servers.	correct	
MC	What does the following query retrieve?<br><br><b>MATCH</b> (p1:Reader)--(b:Book), (p2:Reader)--(p1:Reader)<br><b>WHERE NOT</b> (p2)--(b) <b>AND</b> p1.name='Bart Baesens' <b>AND</b> p2.name='Seppe vanden Broucke'<br><b>RETURN</b> b.title;	A list of books that Bart likes but Seppe doesn't.	correct	A list of books that Bart likes, but none of his friends like.	incorrect	A list of books that both Bart and Seppe like.	incorrect	A list of books that Seppe likes but Bart doesn't.	incorrect	
MC	Which statement is CORRECT?	Document stores are built on the same ideas as key-value and tuple based database systems.	correct	Document stores do not provide SQL-like capabilities.	incorrect	Document stores require that you perform all filtering and aggregation logic in your application.	incorrect	Document stores require users to define document schemas before data can be inserted.	incorrect	
MC	Which statement is NOT CORRECT?	Graphs are mathematical structures consisting of nodes and edges.	incorrect	Graph databases work particularly well on tree-like structures.	incorrect	Graph models are not capable to model many-to-many relationships.	correct	Edges in graphs can be uni- or bidirectional.	incorrect	
MC	When are column oriented databases more efficient?	When many columns of a single group need to be fetched at the same time.	incorrect	When a lot of JOINs need to be performed in queries.	incorrect	When aggregates need to be calculated over many or all rows in the dataset.	correct	When inserts are performed where all of the row data is supplied at the same time.	incorrect	
MC	Which of the following statements on tuple and document stores is correct?	Document stores are always implemented using JSON.	incorrect	Indexes are not possible to define.	incorrect	It has a less rich API than a key-value store.	incorrect	The key can be put in one of the attributes.	correct	
MC	Which of the following statements on the MapReduce model is correct?	The output format of the reduce function does not really matter.	incorrect	Per input entry of a key-value pair, multiple output entries can be produced.	correct	The reduce operation can happen only one and after all the mapping operations have finished.	incorrect	The reduce function cannot be called on partial results.	incorrect