Index
MySQL의 인덱스는 B-Tree 구조
생성
--CREATE
CREATE INDEX index_name ON schema_name.table_name(column_name1, column_name2, column_name3 ...);
--ALTER
ALTER TABLE schema_name.table_name ADD INDEX index_name(column_name1, column_name2, column_name3 ...);
--CREATE
CREATE INDEX index_name ON schema_name.table_name(column_name1, column_name2, column_name3 ...);
--ALTER
ALTER TABLE schema_name.table_name ADD INDEX index_name(column_name1, column_name2, column_name3 ...);