Random Flashcards
____ is a collection of values or information
data
____ is an organized collection of data
database
Three types f data:
structured
semi-structured
unstructured
This type of data is typically stored in tables with predefined structures (ie: schema)
structured data
structured data is suitable for OLTP (transactional) and OLAP (analytical) workloads
T
This type of data is typical of relational databases (indexed tables linked with foreign key relationships)
structured data
this type of data is suited for complex queries an analytics ie: complex table join operaitons
Structured data
This type of data is organized data, but not constrained by a fixed schema
semi-structured data
this type of data the schema accomodates variable data structures
semi-structured data
this type of data is typical of non-relational databases
semi structured data
this type of data is well suited for big data and low latency apps
semi structured data
this type of data is stored as XML and JSON, which makes it easy to read and easy to process
semi structured data
this type of data is unorganized
unstructured data
thistype fo data has no defined schema ie: docs, photos, videos, music, text mesasges, etc.
unstructured data
this type of data is typical ofnon relational databases, file systems, data stores, or data lakes like amazon S3
unstructured data
these types of database have a pre defined schema
relational databases
this type of database enforces a strict ACID compliance and supports “joins”
relational databases
the typical use case for these databases is OLTP and OLAP
relaitonal databaess
MySQL, PostgreSQL, MariaDB, Oracle, SQL Server are examples of this type of DB
relational databases
aws RDS and Aurora for OLTP and redshift for OLAP are types of these databases
relational databases
these types of adtabases are characterized by multiple tables interconencted through foreign key relationships
relational databses
Table INdexes
- relational databases are written to and queried using SQL
- for efficient query performance, we add indexes to the table
- tables are indexed by their primary key by default
- secondary indexed can be added on non-key fields
t
what i ACID?
Atomicity
Consistency
Isolation
Durability
____ means all or nothing - a transaction executes compltely or not at all
Atomicity
____ means once a transaction has been committed, the data must conform to teh given schema
Consistency
____ requires that concurent transactions execute separately from one another
Isolation
____ is the ability to recover form an unexpected system failure or outage
Durability
___ compliance refers only to the compliance enforced by the DB
ACID
ACID behavior an also be enforced by your app:
ie: your app can maintain strict foreign key relationships between two DynamoDB tables. however, dynamoDB by itself will not enfore this relationship. another app can always override this behavior.
if it were mysql tables with relationships defined on teh DB, no app would be able to override the behavior
T
this type of database is sometimes called NoSQL
non relational databases
this type of database is suitable for semi strutured and unstructured data
non relational database
this type of database has data stored in denomalize form
non relational database
this type of database is suited for big data apps
big data = high volume, high velocity, high variety
non-relational database
this type of database is also suited for low latency (high-speed) apps
non-relational databases
this type of database is NOT suited for OLAP
non relational database
this type of database has a flexible data model (trades some ACID properties)
non relational database
BASE =
Basically Available Soft-state Eventually-consistent
_____ ___ - basic R/W operations are available
Basically Available
___ ___ non consistency gurantees, data state may change
Soft-state
____ - data is expected to be consistent over time
Eventually CONsistent
if you prefer high performance over stringly consistent databases, use this…
BASE compliance
- data stored as tables linked trough foreign key relationships
- strict ACID compliance
fixed schema
vertical scaling
uses SQL
suited for OLTP and OLAP
Relational (SQL)
- data stored as collections or key value pairs
- not so strict ACID compliance
-flexible schema (semi structured and unstructured data)
horizontal scaling
- uses object based APIs
- suited forOLTP (web/mobile apps)
Non-Relational (NoSQL)
