Database & Big Data Intro Flashcards
This provides structure for storing data including security, ease of updating, redundancy, size (scalability), accuracy and importance.
A database
Databases typically store 3 types of data. What are they?
- Traditional -numeric
- Multimedia- videos, pictures
- Web- html, xml
A collection of programs that allows us to create and maintain databases.
Database Management System (DBMS)
Databases are used to store data that is what?
interrelated
A database system consists of two things. What are they?
The database and the DBMS
Metadata is stored in what?
The Catalog
Why are concurrency controls needed?
When multiple users access data, rules need to ensure no conflicting operations are executed.
The Data Model is a collection of concepts used to do what?
Determine the structure of the database.
Examples: Data types, relationships, constraints
This data model is the high level model that is similar to how people perceive data.
Conceptual Data Model
This data model can be understood by end users but is not too far removed from how data is organized in computer storage.
Implementation (representational) data model
This data model provides concepts that describe the details of how data is stored.
Physical (low level) data model
The database schema is what?
The description of the database, which shouldn’t change much/often.
Table names, columns, relationships, etc.
The current state of the database is called what?
The Database instance
The Three-Scheme Architecture contains what 3 pieces?
External view- what users can see
Conceptual Schema- how database is set-up
Internal Schema- how it’s stored
Data Definition Language (DDL) is a type of DBMS Language. What is it used for?
Used by DBAs to define the schemas.
