©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
NoSQL Exam Study Guide.
LECTURE 19: NoSQL (11/19)
examples of NoSQL databases - answer✔big data, cassandra, dynamo, Hbase, MongoDB,
voldemort
4 NoSQL types - answer✔-key-value stores (redis, riak, voldy)
-document stores (mongo)
-graph database (neo4j)
-column-family stores (cassandra, hbase)
examples of key-value stores - answer✔-Redis
-Riak
-Voldemort
examples of document stores - answer✔-MongoDB
examples of graph database - answer✔-Neo4j
examples of column-family stores - answer✔-Cassandra
-HBase
define key-value stores - answer✔-key might be customer number
-value is whatever you like
-value can be structured data or unstructured
define column-family stores - answer✔-a single row key maps to multiple collections of data
-like a two-level map
-row key -> column-family -> column key -> column value
define document-based stores - answer✔-database us a collection of documents
1|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
-often JSON
-document often has some unique ID
define graph databases - answer✔-similar to object-oriented structures
-nodes are entities with properties
-edges are relationships
-good for graph-like queries (e.g. shortest path)
aggregates - answer✔-the unit of storage, some meaningful chunk of data
-ie. student, course names, grades, GPA
implicit schema - answer✔NoSQL dbs are sometimes called schema-less
-denormalized, not 1NF!
NoSQL query types - answer✔-no complex queries
-no SQL support
-CRUD operations via API (create, read, update, delete)
NoSQL joins - answer✔no join support
NoSQL transactions - answer✔no transaction support
NoSQL consistency - answer✔-different from ACID
-consistency-- reads get the latest value
-most NoSQL dbs only provide EVENTUAL CONSISTENCY
--reads will *eventually* get the value of the latest write
CAP theorem - answer✔(Brewer) it's imposs to satisfy more than 2 of the following:
-consistency: reads get the latest value
-availability: every request gets a response
-partition tolerance: system tolerates network delays/failures
--if the network is working, all is well
----satisfy consistency & availability
2|Page
ALL RIGHTS RESERVED.
NoSQL Exam Study Guide.
LECTURE 19: NoSQL (11/19)
examples of NoSQL databases - answer✔big data, cassandra, dynamo, Hbase, MongoDB,
voldemort
4 NoSQL types - answer✔-key-value stores (redis, riak, voldy)
-document stores (mongo)
-graph database (neo4j)
-column-family stores (cassandra, hbase)
examples of key-value stores - answer✔-Redis
-Riak
-Voldemort
examples of document stores - answer✔-MongoDB
examples of graph database - answer✔-Neo4j
examples of column-family stores - answer✔-Cassandra
-HBase
define key-value stores - answer✔-key might be customer number
-value is whatever you like
-value can be structured data or unstructured
define column-family stores - answer✔-a single row key maps to multiple collections of data
-like a two-level map
-row key -> column-family -> column key -> column value
define document-based stores - answer✔-database us a collection of documents
1|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
-often JSON
-document often has some unique ID
define graph databases - answer✔-similar to object-oriented structures
-nodes are entities with properties
-edges are relationships
-good for graph-like queries (e.g. shortest path)
aggregates - answer✔-the unit of storage, some meaningful chunk of data
-ie. student, course names, grades, GPA
implicit schema - answer✔NoSQL dbs are sometimes called schema-less
-denormalized, not 1NF!
NoSQL query types - answer✔-no complex queries
-no SQL support
-CRUD operations via API (create, read, update, delete)
NoSQL joins - answer✔no join support
NoSQL transactions - answer✔no transaction support
NoSQL consistency - answer✔-different from ACID
-consistency-- reads get the latest value
-most NoSQL dbs only provide EVENTUAL CONSISTENCY
--reads will *eventually* get the value of the latest write
CAP theorem - answer✔(Brewer) it's imposs to satisfy more than 2 of the following:
-consistency: reads get the latest value
-availability: every request gets a response
-partition tolerance: system tolerates network delays/failures
--if the network is working, all is well
----satisfy consistency & availability
2|Page
