Domain 8: Databases Flashcards
Controls all access to the database and enforces the database security
Database Management System (DBMS)
- Allows for searching within a database
- i.e. Structured Query Language (SQL)
Query language
- Creates relationships between records in tables by using a primary key
- Contains two-dimensional tables made up of rows and columns
Relational database
Another name for a table
Relation
Row in a database
Tuple
Database column
Attribute
Single cell in a database
Value
Contains the data in a database
Cell
- Selected from the set of candidate keys inside a table
- Used to uniquely identify the records in a table
- Relational databases require unique value in each tuple in a table
Primary Key
Any attribute (column) in the table with unique values
Candidate Keys
- Key in a relational database table that matches a primary key in a parent database table
- Used to enforce relationships between two tables
Foreign Key
- Means that every foreign key in a secondary table matches a primary key in the parent table
- If not this is not true, integrity has been broken
Referential Integrity
Means each attribute (column) value is consistent with the attribute data type
Semantic Integrity
Means each tuple has a unique primary key that is not null
Entity Integrity
- Removes redundant data
- Purpose is to make data in a database table concise, organized and consistent
Database normalization
- Virtual tables you can query like a table
- Doesn’t store data
- Can combine data from two or more tables using joins
- Can be used to implement multilevel security
Database View
Allows the creation of database tables, read/write access to those tables, and many other functions
Database query languages
What are the two subset of commands for Database query languages?
- Data definition language (DDL)
2. Data manipulation language (DML)
Used to create, modify, an delete tables
Data definition language (DDL)
Used to query and update data stored in the tables
Data manipulation language (DML)
- Combine data with functions (code) in an code-accessible framework
- Data and functions form an object
- Objects can then be accessed, read, and, written to by using code written in an _____ programming language
Object-oriented databases
- Log of all database transactions
- If database becomes corrupted, this can be used to restore the database
Database journal
- Allows simultaneous reads and writes to multiple replicated databases by clients
- Provides a means of backing up an entire database or of creating high availability and redundancy
Database Replication
Mirrors all database changes made to primary, but clients do not have access to this copy
Database Shadowing
- Combines records and fields that are related in a logical tree structure (one-to-many)
- i.e. Organization chart, NCAA March Madness bracket system, DNS
Hierarchical database model
