Lecture 4 Flashcards
OLTP?
Online Transaction Processing
OLAP
Online Analytical Processing
Where is OLTP used?
E-commerce
Banking
Airline Reservations
OLTP (User facing)
Real-Time
Low latency
Highly-concurrent
OLTP (Tasks)
Relatively small set of standard transactional queries
OLTP (Data access pattern)
Random leads
Updates
Writes
Where is OLAP used?
Business intelligence
Data mining
OLAP (Back-end processing)
Batch workloads
Less concurrency
OLAP (Tasks)
Complex analytical queries
Ad-hoc
OLAP (Data access pattern)
Table scans
Large amounts of data involved per query
OLAP Example?
Amazon analyzes purchases by its customers to come up with an individual screen with products of likely interest to the customer
Downsides of co-existing OLTP and OLAP workloads?
Poor memory management
Conflicting data access patterns
Variable latency
Solution for having both OLTP and OLAP with no downsides?
Separate databases
User-facing OLTP database for high-volume transactions
Data warehouse for OLAP workloads
How to connect OLTP with OLAP?
ETL
What does ETL stand for?
Extract
Transform
Load
`What is Data Warehouse?
A physical repository where relational data are specially organized to provide enterprise-wide, cleansed data in a standardized format
Characteristics of DWs?
Subject oriented Integrated Time-variant Nonvolatile Summarized Not normalized Metadata Web based Client/server
What is Data Mart?
A departmental small-scale DW that stores only limited/relevant data
Two types of Data Mart?
Dependent data mart
Independent data mart
Dependent data mart?
A subset that is created directly from a data warehouse
Independent data mart?
A small data warehouse designed for a strategic business unit or a department
Other DW Components?
ODS
Oper marts
EDW
Metadata
ODS?
Operational Data Stores
A type of database often used as an interim area for a data warehouse