Database Management Systems · topic
Selection, projection, rename, union, difference, product and the derived intersection, joins and division; result schemas and size bounds; set versus bag semantics; theta, equi, natural, semi and outer joins; equivalence rules and how to disprove a claimed equivalence with a small instance.
Relational algebra is a procedural query language: a query is an expression built from operators that take relations and return a relation. Because the output of every operator is again a relation, operators compose freely, and an expression reads like a pipeline.
One-page visual sheets for this topic, in the sheet library on the store. Previews are free; the full sheets come with the subject pack.
