CREATE INDEX

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CREATE INDEX

The table games shows the year and the city hosting the Olympic Games.

games
yrcity
2000Sydney
2004Athens
2008Beijing
2012London
schema:scott
 DROP TABLE games
 CREATE TABLE games(
  yr INTEGER PRIMARY KEY,
  city VARCHAR(20));
INSERT INTO games VALUES (2000,'Sydney');
INSERT INTO games VALUES (2004,'Athens');
INSERT INTO games VALUES (2008,'Beijing');
INSERT INTO games VALUES (2012,'London');

When you create an index you make it faster to find a particular row. You can also make the JOIN operator faster.

CREATE INDEX gamesIdx ON games(city,yr);
SELECT yr, city FROM scott.games
CREATE INDEX gamesIdx ON games(city,yr);
SELECT yr, city FROM games

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