CompTIA Data+ Exam DA0-001 - Lesson 1 Flashcards
Identifying Basic Concepts of Data Schemas
Relational Databases
- Relational Database Management System (RDBMS): Software used to maintain relational databases.
- Tables: Used to store captured data.
- Table Components:
- Fields (Field Names): Columns in the table.
- Rows: Records of the data in the table.
- Data Type: Each column has a specific data type.
- SQL (Structured Query Language): Language used to query and manage data in relational databases.
Non-Relational Databases
- NoSQL: Alternative to relational SQL databases.
- Usage: Ideal for web-based databases that handle large amounts of traffic and data.
- Scalability: Easier to scale for web applications.
- Four Basic Categories:
- Document-oriented databases
- Key-value stores
- Column-oriented databases
- Graph stores
Review Activity: Relational and Non-Relational Databases
- Question: Which database type is suitable when a defined structure with relationships within the data is needed?
- Question: What are the two main components of a table design?
- Question: Which database type stores data in document format and uses XML or JSON?
- Question: What language is used for relational databases?
- Question: Which database type provides the most scalable and flexible option for web-based applications?
Lab Activity
- Lab Types:
- Assisted labs: Step-by-step guidance through tasks.
- Applied labs: Goals set with limited guidance.
- Complete Lab:
- Submit all items for grading.
- Check each progress box.
- Select “Grade Lab” from the final page.
- Save Lab:
- Select the hamburger menu and select “Save.”
- Save up to two labs in progress for up to 7 days.
- Cancel Lab Without Grading:
- Select the hamburger menu and select “End.”
Tables, Primary Keys, & Normalization
Normalization
- Data is structured for optimal storage and use within the program.
- Normalized Data: Structured data.
- First Normal Form (1NF):
- Eliminates redundant information in individual tables.
- Each set of related data is stored in a dedicated table.
- Each table of related information has a primary key assigned.
- Second Normal Form (2NF):
- Related information applicable to multiple tables has its own table.
- Tables are associated through the use of a foreign key.
- Third Normal Form (3NF):
- Eliminates fields that do not depend on a key.
- Most designs do not go to the 3NF.
Primary Key and Foreign Key Relationships
- Primary Key: A key used to uniquely identify a record.
- Foreign Key: A primary key used in another table to refer to the record.
| Attribute | Primary Key | Foreign Key |
|---|
| Consists of Columns | Yes | Yes |
| Duplicate Values | No | Yes |
| NULLs Allowed | No | Yes |
| Uniquely Identify Rows | Yes | Sometimes |
| Number per table | One | Zero or More |
| Indexed | Automatically | No Index |
| Automatically Created | | Indexed |
Types of Relationships
- One-to-one relationship
- One-to-many relationship
- Many-to-many relationship
Referential Integrity
- Ensures that the foreign key has a primary key in the related table.
- Cascade Update: When a primary key is changed, and cascade update is enforced, the primary key will change in all other related tables.
- Cascade Delete: When a primary key record is deleted, and cascade delete is enforced, all records in various tables related to the record through that key will be automatically deleted.
Review Activity: Tables, Primary Keys, and Normalization
- Question: What elements of a database are necessary for tables to establish relationships?
- Question: To ensure data updates effectively across tables, what can be set on the relationships between tables?
- Question: When the design of the data forces a person to repetitively enter the same information, this data would be considered .
- Question: A database architect creates a design in which a table has a primary key and associated fields. This is an example of what type of design theory?