Week 5 - Key Value Stores

Question 1

Four Requirements of NoSQL

Answer 1

1) Availability
2) Scalability
3) Fault Tolerance
4) Manageability

Question 2

Amazon Dynamo 4 items

Answer 2

1) simple Read /Write operations to data with IDs
2) No operations span multiple records
3) Data stored as Binary objects of small size
4) Eventual consistency

99.9 optimized

Question 3

Data model has two functions

Answer 3

1) Put

2) get

Question 4

To achieve load balancing also you need to ____ the nodes

Answer 4

HASH

method: contestant hashing

Question 5

contestant hashing data is stored as a

Answer 5

nodes in a ring (clockwise)

Question 6

semantic reconciliation?

Answer 6

semantic reconciliation is conflict resolution

So that means the system does not understand the semantics, the system understands key value and that’s all, right?

So in that case, the conflict resolution is pushed to the application.

Question 7

Google BigTable is

Answer 7

Column based

Google BigTable or like a column family-based
databases or column family-based data stores, they come in the middle.

So you still have some kind of a row representation
but the row representation is not as rigid,
does not have a rigid schema as in the relational database.

Question 8

Google BigTable locking service

Answer 8

Chubby

Question 9

What is the BigTable SSTable?

Answer 9

SSTable is a file of key/value string pairs, sorted by keys

SSTable stands for Sorted Strings Table a concept borrowed from Google BigTable which stores a set of immutable row fragments in sorted order based on row keys.

SSTable files of a column family are stored in its respective column family directory.