In the previous section, we observed that it would not make much sense for a user to have a graduation year without also naming an educational institution; this provided a rather abstract motivation for grouping those two pieces of information together in a single column. A more practical motivation is the fact that, like any other column, tuples can be indexed.
Let's put an index on our education column; the syntax is no different from creating an index on any other column:
CREATE INDEX ON "users" ("education");
Armed with this index, we can now perform efficient lookup of user records based on their educational institution and year of graduation:
SELECT "username", "education" FROM users WHERE "education" = ('Big Data ...
