Week 12A (Data Storage and Flow Management)

Question 1

basic idea of nosql databases

Answer 1

operate without a schema

Question 2

when are nosql databases used

Answer 2

useful when dealing w/ non-uniform or custom fields

can add fields w/o defining change in structure first

Question 3

in nosql key value storage how is a value treated

Answer 3

just as a blob, application is responsible for understanding data

Question 4

suitable usecases for nosql key val storage

Answer 4

session info

user prof, pererfences

shopping cart data

Question 5

non-suitable usecases for nosql key val

Answer 5

relationships between data

multi operation transactions

query by data (theres no way to inspect value on server side)

Question 6

in nosql document storage where are documents stored

Answer 6

in val part of the key-val store

Question 7

in nosql document storage what are documents

Answer 7

contains data structure (maps, tres, collections)

Question 8

suitable usecases for nosql document storage

Answer 8

event logging

blogging platforms

Question 9

non-suitable usecases for nosql document storage

Answer 9

complex transactions spanning diff ops

queries against varying aggregate structure

Question 10

in nosql col value store where is data stored

Answer 10

in column family as rows

Question 11

in nosql col value store what is a colunmn family

Answer 11

groups of related data that is often accessed together

Question 12

what type of db is google big table

Answer 12

nosql column family

Question 13

how do you store semi structured data at scale

Answer 13

google bigtable

nosql col family

Question 14

what is data in bigtable

Answer 14

uninterpreted strings

Question 15

in bigtable, how are large tablets broken down

Answer 15

into tablets, they hold a contiguous range of rows

Question 16

Each cell in Bigtable can contains multiple versions of the same data, how is this fixed

Answer 16

indexed by timestamp. most recent versions can be read first

Question 17

What is Google SSTable (Sorted String Table)

Answer 17

persistently ordered immutable map from key to values

keys and vals are arbitrary byte strings

Question 18

in bigtable, how are tablets located

Answer 18

give the bigtable master the row you want, and itll point you to right machine