Chapter 4: Summary book Flashcards
What is data
Data are the raw bits and pieces of information with no context
What is quantitative data
Quantitative data is numeric, the result of a measurement, count, or some other mathematical calculation.
What is qualitative data
Qualitative data is descriptive.
What is information
For data to be useful it needs to be given context, it then turns into information.
What is knowledge
Once you have put data into context, aggregated and analysed it, you can use it to make decisions for your organization. This consumption of information produces knowledge, which can be used to make decisions, set policies, and even spark innovation
What is wisdom
The final step is wisdom, which is reached when combining knowledge and experience to produce a deeper understanding of a topic.
What is the goal of information systems
The goal of many information systems is to transform data into information to generate knowledge that can be used for decision making.
What is a database
A database is an organized collection of related information. All the data is described and associated with other data and all the information should be related as well.
What is a relational database
A relational database is one in which data is organized into one or more tables (e.g. MySQL and Oracle). SQL is a language that can be used to work with a relational database.
What has a table?
Each table has a set of fields (column), which define the nature of the data stored in the table. A record (row) is one instance of a set of fields in a table. For each table, one of the fields is identified as a primary key. This key is the unique identifier for each record in the table (e.g. e-mail address).
What is needed to design a database
- Determine which tables need to be created.
- Identify which fields will be in each table (every table should have a field in common with another table).
- Select a primary key for every table.
What is needed to normalize a database
- reduces duplication of data between tables
2. it gives the table as much flexibility as possible.
What is a database management system (DBMS)
A database management system (DBMS) is a software application that is used to create and manage databases, and can take the form of a personal DBMS, used by one person, or an enterprise DBMS that can be used by multiple users.
What is a data warehouse and which criteria does it have?
A data warehouse is a special form of database that takes data from other databases in an enterprise and organizes it for analysis. It should be designed so that it meets the following criteria:
- It uses non-operational data, meaning a copy of the data from an active database.
- The data it time-variant, which means that the data receives a time stamp.
- The data is standardized.
How goes the bottom-up and top-down approach of designing a data warehouse?
Bottom-up: ERP, Marketing, HR, Sales -> ETL (Extraction - Transformation - Load) -> Data warehouse -> Data mart (small data warehouses)
Top-down: reverse
