Join Operators in DBMS

Cartesian product returns all the possible associations among the relations. Out of these only a subset of rows would be returned by the join operators.

Join operators can be divided in two such categories:

  1. Join Type
  2. Conditions
Types Conditions
Inner Natural (Equi Join)
Left Outer ON Condition
Right Outer Using Attributes
Full Outer or Outer

Join Types:

Signifies the following points

  • The decision on the types of rows returned that is matched or un-matched rows.
  • The procedure of placing the matched rows in the result based on the requirements.

Join Conditions:

Signifies the following points

  • The predicate that shall get applied while joining the tables. The predicate shall get used in evaluating whether a row is matched or not.
  • Join condition also signify list of columns that are allowed in the result set.

Join Types in detail

Join condition in detail



One comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.