Projection (relational algebra)
= Projection (relational algebra)
{wiki=Projection_(relational_algebra)}
In relational algebra, **projection** is a fundamental operation that allows you to retrieve specific columns from a relational database table. It is used to create a new relation (table) that contains only the specified attributes (columns) from the original relation, effectively filtering out the unwanted ones. The projection operation is denoted by the symbol π (the Greek letter pi).