[MySql] 인덱스추가

인덱스의 추가(ALTER TABLE)
  ALTER TABLE tblname ADD INDEX indexname (index_columns);
  ALTER TABLE tblname ADD PRIMARY KEY indexname (index_columns);
  ALTER TABLE tblname ADD UNIQUE indexname (index_columns);

인덱스의 추가(CREATE INDEX)
  CREATE INDEX indexname ON tblname (index_columns);
  CREATE UNIQUE INDEX indexname ON tblname (index_columns);
  CREATE PRIMARY KEY indexname ON tblname (index_columns);


인덱스의 추가(CREATE TABLE)
  CREATE TABLE tblname
  (
    i INT NOT NULL PRIMARY KEY,
    sz CHAR(10) NOUT NULL UNIQUE
  );

인덱스의 삭제
  DROP INDEX indexname ON tblname;
  DROP INDEX 'PRIMARY' ON tblname; (PRIMARY KEY 삭제)
  ALTER TABLE tblname DROP INDEX indexname;
  ALTER TABLE tblname DROP PRIMARY KEY;