Lesson 2 Flashcards
(26 cards)
A class of software that allows large numbers of database transactions in real-time, typically over the internet
Online transactional processing (OLTP)
Any change to data in a system, whether it’s an insertion, deletion, or query
database transaction
A class of software that allows complex analysis to be conducted on large databases without negatively affecting transactional systems
Online transactional processing (OLAP)
The system of record for any given element or piece of information
Source system
Technology that is dedicated to the storage of company data from a wide range of sources for reporting and decision-making purposes
Data warehouse
A subset of the data warehouse that is dedicated to a specific department or group
Data mart
Holds the “facts” about a particular business process or event and contains keys to relate to the other tables
Fact table
Holds attributes or the categorical information that supports the fact tables
Dimension table
The relational model of fact and dimension tables that looks like a star, in which all dimension tables are joined to a single fact table
Star schema
The relational model of fact and dimension tables that looks like a snowflake, in which dimension tables are joined to a single fact table and also other dimension tables
Snowflake schema
A technology for storing large amounts of structured and unstructured types of information in their original format
data lake
A data management system that combines the best of both data warehousing and data lakes
data lakehouse
A way of updating dimension data
Slowly changing dimensions
Overwrites the existing value in a field of data with a new value and does not retain the history of that field
Slowly Changing Dimension Type 1
Adds a new row for the new value and also maintains the historical record
Slowly Changing Dimension Type 2
Adds a new column for the current value but also retains the original column with the original value
Slowly Changing Dimension Type 3
Which subset of a data warehouse holds data that is relevant to a specific department?
Datamart
What is the most flexible storage system for holding large amounts of both structured and unstructured data?
Data lake
In an organization, which technology holds a system of record, or is a software system dedicated to a specific task?
Source system
What choices do organizations have when they want to combine data from different source systems into one unified data management system?
Data warehouses, data lakes, and data lakehouses
What type of table stores information that is categorical for the use of reporting?
Dimension tables
What are two common schemas that are used to relate data in a data warehouse?
Star schema and snowflake schema
What process does slowly changing dimensions describe?
Three ways to change dimension data in a system. There are three types: Type 1, Type 2, and Type 3
Which type of slowly changing dimension is in use when a new record is added to account for a change to dimension data?
Type 2
