我们来学mysql -- 查询成本之索引选择(原理篇)
CREATE TABLE `test`.`Untitled` (
`id` int(0) NOT NULL AUTO_INCREMENT,
`k1` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`k2` int(0) NOT NULL,
`k3` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
`k_part1` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`k_part2` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`k_part3` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`mark` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE,
INDEX `idx_key1`(`k1`) USING BTREE,
UNIQUE INDEX `uk_key2`(`k2`) USING BTREE,
INDEX `idx_key3`(`k3`) USING BTREE,
INDEX `idx_key_part`(`k_part1`, `k_part2`, `k_part3`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 20001 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;