Chapter 1 - Data Sources¶

Contents¶

Term	Definition	Notes
API	Application Programming Interface
SQL	Structured Query Language
RDBMS	Relational Database Management System
ODBC	Open Database Connectivity	Uses drivers to standardize interfaces between software applications and database.
ERD	Entity Relationship Diagram
Foreign Key	Primary Key referenced by another table as a constraint

Unstructured:

Structured:

Database = Collection of tables
Database Schema = Stores table information and relationships (i.e. defines the structure)

Where a unique entity only occurs in one table once but can have multiple entries in another
e.g., patient tbl and appointments tbl

Connection between entities where records on each side of the relationship can connect to multiple records on the other side
Junction of associated table needs to capture the pairs of related rows
Allows the ability to reduce the amount of redundant data stored in the database

Often contain data from multiple underlying sources
may contain row and summary data
Can contain historical data logs, etc
Star scheme design (pg 7)
Divides data into facts/dimensions
- Facts tbl = metadata of an entity and measures
- Dimension tbl = property of entity you can group or “slice and dice” the fact records by, get further info, etc
Table grain
level of detail; what set of columns makes a row unique
Database roles
SME’s = subject matter experts
DBA’s = Database administrators
ETL engineers = PEople who extract, transform, and load data from a source system into a data warehouse