Database Concepts - Formula Sheet
Database Concepts - Formula Sheet
This sheet summarizes the core query operators and logical notations used in relational algebra calculations.
| Operation Name | Operator Notation | Functional Meaning |
|---|---|---|
| Select Operation | σc(R) | Extracts a subset of tuples (rows) from relation R that satisfy the filtering condition c. |
| Project Operation | ΠL(R) | Extracts specific columns defined in list L from relation R and discards duplicate rows. |
| Union Operation | R ∪ S | Combines all unique records from both relation R and S; requires union-compatible schemas. |
| Set Difference | R − S | Finds all tuples present in relation R but completely absent in relation S; requires union compatibility. |
| Intersection Operation | R ∩ S | Identifies tuples present simultaneously in both relation R and S; requires union compatibility. |
| Cartesian Product | R × S | Combines every tuple from relation R with every tuple from relation S to generate all possible pairings. |
More for this chapter
Book Back Questions10 textbook MCQs · solved
Additional MCQs15 extra MCQs · solved
Practice TestInteractive · instant score
Book Back TestTest yourself on the textbook set
Additional MCQ TestTest yourself on the extra set
Study NotesConcepts & methods
More chapters in Computer Science
View all
1 Function
2 Data Abstraction
3 Scoping
4 Algorithmic Strategies
5 Python -Variables and Operators
6 Control Structures
7 Python functions
8 Strings and String manipulation
9 Lists, Tuples, Sets and Dictionary
10 Python Classes and objects
12 Structured Query Language (SQL)
13 Python and CSV files
14 Importing C++ programs in Python.
15 Data manipulation through SQL
16 Data visualization using pyplot: line chart, pie chart and bar chart