FANDOM


Relational Algebra is a set of mathematical principles that allow for the manipulation of the contents in a relational table. Relational Algebra is procedural, meaning the SQL that is written will execute in the order that it was written. It is a set at a time process which means that it will process sets of data instead of individual tuples of data.Relational Calculus is also a set of mathematical principles that allow for the manipulation of the contents in a relational table. It is a set at a time process which means that it will process sets of data instead of individual tuples of data.However Relational Calculus is a non-procedural process which means that the written SQL does not have to be done in the order it was written.



Relational Algebra has 8 operations it can perform:


SELECT - Yields values for all rows found in a table, can be used to list either all row values or it can yield only those row values that match a specific criteria, and yields a horizontal subset of a table.


PROJECT - Yields all values for selected attributes and yields a vertical subset of a table.


JOIN - Allows the combination of information from two or more tables and allows the use of independent tables linked by common attributes.


INTERSECT - Yields all the rows that appear in both tables.


- Combines all rows from two tables, excluding duplicate rows, but tables must have the same attribute characteristics.


DIFFERENCE - Yields all rows in one table not found in the other table.


CARTESIAN PRODUCT - Yields all possible pairs of rows from two tables.


DIVIDE - Requires the use of one single-column table and one two-column table.


The 5 operations that can create the other operations are: SELECT, PROJECT, , CARTESIAN PRODUCT, and DIFFERENCE.


Relational Calculus has 3 operations it can perform:


SELECT - Is a restrict operation that yields all rows and specified columns based on the level of restrict.


INTERSECT - Yields all rows that appear in both tables.


- Combines all rows from two tables, excluding duplicate rows, but tables must have the same attribute characteristics.

Ad blocker interference detected!


Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.