Relational Algebra - 101

This blog post as most others here is in a "notes to myself" category , in case its useful to any other reader - well thats great , i dont really have the time to create very readable user focused content as on date .

A relational database is composed of two-dimensional tables. (A table can also be called a relation, although relational "purists" would argue that there is a subtle distinction between the two.) Each "row" of a table is called a tuple. Each tuple is composed of fields, one for each attribute of the table. (The attributes are the names we associate with the fields/columns.)  SOURCE =
https://www.cs.scranton.edu/~mccloske/courses/cmps340/rel_alg_intro_lec.html

Above image SOURCE == https://medium.com/@sahirnambiar/relational-algebra-the-underpinnings-of-sql-74959481231a

1. RENAMING --- 
2. SELECTION ---
3. PROJECTION ---

Further Readings and the main SOURCE for the Content of this Blog post --  Kindly note due credit goes to each and every of these links 

StanfordDBClass - YouTube - https://www.youtube.com/watch?v=tii7xcFilOA

https://www.cs.scranton.edu/~mccloske/courses/cmps340/rel_alg_intro_lec.html

https://www.cs.helsinki.fi/u/laine/tkpv/algebra/buildingqueries.html
 
https://db.grussell.org/section010.html 

https://www3.cs.stonybrook.edu/~kifer/Courses/cse532/slides/ch5.pdf

https://www.cs.uct.ac.za/mit_notes/database/htmls/chp02.html

https://www.javatpoint.com/dbms-relational-algebra

https://www.guru99.com/relational-algebra-dbms.html

http://www.databasteknik.se/webbkursen/relalg-lecture/index.html

https://web.cs.ucdavis.edu/~green/courses/ecs165a-w11/3-ra.pdf

http://www.nyu.edu/classes/jcf/CSCI-GA.2433-001_sp15/slides/session5/RelationalAlgebra-RelationalCalculus-SQL.pdf

https://www.studytonight.com/dbms/relational-algebra.php

https://beginnersbook.com/2019/02/dbms-relational-algebra/

https://www3.cs.stonybrook.edu/~kifer/Courses/cse532/slides/ch5.pdf
https://www.guru99.com/relational-algebra-dbms.html
https://www.studytonight.com/dbms/relational-algebra.php

http://dinesql.blogspot.com/2017/06/relational-algebra-joins-theta-join-equijoin-natural-join-outer-join-semijoin.html