MC When are column oriented databases more efficient? When a lot of JOINs need to be performed in queries. incorrect When many columns of a single group need to be fetched at the same time. incorrect When inserts are performed where all of the row data is supplied at the same time. incorrect When aggregates need to be calculated over many or all rows in the dataset. correct
MC When are column oriented databases more efficient? When aggregates need to be calculated over many or all rows in the dataset. correct 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 inserts are performed where all of the row data is supplied at the same time. incorrect
MC Which of the following statements describes NoSQL databases best? NoSQL databases do not support joins. incorrect NoSQL databases are non-relational. correct A NoSQL database offers no support for SQL. incorrect NoSQL databases are not capable to deal with large datasets. incorrect
MC Which statement is NOT CORRECT? Column oriented databases are more efficient when many columns of a single group need to be fetched at the same time. correct By using the membership protocol, the system can only achieve eventual consistency. incorrect Using the membership protocol in the context of request coordination, a failed node will be detected if it stops responding to other nodes. This information will then be disseminated through the entire network. incorrect Vertical scaling is limited by hardware performance. incorrect
MC Using Cypher, how do you get a list of all movies Wilfried Lemahieu has liked, when he has given at least four stars? MATCH (b:User)--(m:Movie)
WHERE b.name = "Wilfried Lemahieu"
AND l.stars >= 4
RETURN m incorrect SELECT (b:User)--m:Movie)
WHERE b.name = "Wilfried Lemahieu"
AND m.starts >= 4 incorrect MATCH (b:User)-[I:LIKES]-(m:Movie)
WHERE b.name = "Wilfried Lemahieu"
AND m.stars >=4
RETURN m incorrect MATCH (b:User)-[I:LIKES]-(m:Movie)
WHERE b.name = "Wilfried Lemahieu"
AND l.stars >= 4
RETURN m correct
MC Which statement is CORRECT? The fact that most NoSQL databases adopt an eventual consistency approach is due to the CAP theorem, which states that strong consistency cannot be obtained when availability and partitioning has to be ensured. correct Some relational constructs, such as the many-to-many relationship, are harder to express using graph databases. incorrect Stabilization relates to the waiting time between the start-up of a NoSQL system and when the system becomes usable to receive user queries. incorrect Replicas in a distributed NoSQL environment relate to making periodic backups of the database to a second system. incorrect
MC Which statement is NOT CORRECT? Graph models are not capable to model many-to-many relationships. correct Graphs are mathematical structures consisting of nodes and edges. incorrect Edges in graphs can be uni- or bidirectional. incorrect Graph databases work particularly well on tree-like structures. incorrect
MC When are column oriented databases more efficient? When inserts are performed where all of the row data is supplied 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 many columns of a single group need to be fetched at the same time. incorrect
MC Which statement is CORRECT? The soft state property of the BASE principle indicates that a system can only change over time if it receives input. incorrect Column oriented databases are more efficient when many columns of a single group need to be fetched at the same time. incorrect Graph models are not capable to model many-to-many relationships. incorrect A ring-topology can be used to achieve consistent hashing. correct
MC Which statement is CORRECT? The fact that most NoSQL databases adopt an eventual consistency approach is due to the CAP theorem, which states that strong consistency cannot be obtained when availability and partitioning has to be ensured. correct Replicas in a distributed NoSQL environment relate to making periodic backups of the database to a second system. incorrect Some relational constructs, such as the many-to-many relationship, are harder to express using graph databases. incorrect Stabilization relates to the waiting time between the start-up of a NoSQL system and when the system becomes usable to receive user queries. incorrect