Mysql使用中的性能优化——索引数对插入操作性能的影响

表的索引可以给数据检索提升效率，但是也给表的增删改操作带来代价。本文我们将关注，索引数量对INSERT操作的影响。

结论

索引数的新增会造成INSERT操作效率下降，约每增一个索引会降低10%效率。

实验数据

在这里插入图片描述
可以看到0个索引的效率是7个索引效率的一倍。

测试环境

见《Mysql使用中的性能优化——搭建Mysql的监测服务》

测试代码

DROP DATABASE IF EXISTS testdb;
CREATE DATABASE IF NOT EXISTS testdb;
USE testdb;

DROP TABLE IF EXISTS test_insert_src;
CREATE TABLE test_insert_src (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_0_index;
CREATE TABLE test_insert_0_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_1_index;
CREATE TABLE test_insert_1_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_2_index;
CREATE TABLE test_insert_2_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_3_index;
CREATE TABLE test_insert_3_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_4_index;
CREATE TABLE test_insert_4_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_5_index;
CREATE TABLE test_insert_5_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32)),
    INDEX name4_index (name4(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_6_index;
CREATE TABLE test_insert_6_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32)),
    INDEX name4_index (name4(32)),
    INDEX name5_index (name5(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_7_index;
CREATE TABLE test_insert_7_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32)),
    INDEX name4_index (name4(32)),
    INDEX name5_index (name5(32)),
    INDEX name6_index (name6(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_8_index;
CREATE TABLE test_insert_8_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32)),
    INDEX name4_index (name4(32)),
    INDEX name5_index (name5(32)),
    INDEX name6_index (name6(32)),
    INDEX name7_index (name7(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_9_index;
CREATE TABLE test_insert_9_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32)),
    INDEX name4_index (name4(32)),
    INDEX name5_index (name5(32)),
    INDEX name6_index (name6(32)),
    INDEX name7_index (name7(32)),
    INDEX name8_index (name8(32))
) engine=InnoDB;

DROP TABLE IF EXISTS test_insert_10_index;
CREATE TABLE test_insert_10_index (
    id SERIAL PRIMARY KEY,
    name TEXT,
    name1 TEXT,
    name2 TEXT,
    name3 TEXT,
    name4 TEXT,
    name5 TEXT,
    name6 TEXT,
    name7 TEXT,
    name8 TEXT,
    name9 TEXT,
    INDEX name_index (name(32)),
    INDEX name1_index (name1(32)),
    INDEX name2_index (name2(32)),
    INDEX name3_index (name3(32)),
    INDEX name4_index (name4(32)),
    INDEX name5_index (name5(32)),
    INDEX name6_index (name6(32)),
    INDEX name7_index (name7(32)),
    INDEX name8_index (name8(32)),
    INDEX name9_index (name9(32))
) engine=InnoDB;

DROP PROCEDURE IF EXISTS test_insert_proc_batch_bulk;
DELIMITER //
CREATE PROCEDURE test_insert_proc_batch_bulk(IN name TEXT, IN fromNum INT, IN toNum INT)
BEGIN
    DECLARE i INT DEFAULT fromNum;
    DECLARE j INT DEFAULT 0;
    DECLARE new_names TEXT DEFAULT '';
    DECLARE nameList TEXT DEFAULT '';
    SET @sql = 'INSERT INTO test_insert_src (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) VALUES ';
    WHILE i < toNum DO
        SET nameList = '';
        SET j = 0;
        while j < 10 DO
            SET new_names = CONCAT(name, i, "_", j);
            IF j = 0 THEN
                SET nameList = CONCAT(nameList, '"', new_names, '"');
            ELSE
                SET nameList = CONCAT(nameList, ',"', new_names, '"');
            END IF;
            SET j = j + 1;
        END WHILE;
        SET i = i + 1;
        SET @sql = CONCAT(@sql, '(', nameList, '),');
    END WHILE;
    SET @sql = LEFT(@sql, LENGTH(@sql) - 1);
    PREPARE stmt FROM @sql;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;
    COMMIT;
END //
DELIMITER ;

DROP PROCEDURE IF EXISTS test_insert_proc_batch;
DELIMITER //
CREATE PROCEDURE test_insert_proc_batch(IN name TEXT, IN count INT, IN step INT)
BEGIN
    DECLARE i INT DEFAULT 0;
    WHILE i < count DO
        CALL test_insert_proc_batch_bulk(name, i, i + step);
        SET i = i + step;
    END WHILE;
    COMMIT;
END //
DELIMITER ;

TRUNCATE TABLE test_insert_src;
CALL test_insert_proc_batch('test', 1000000, 5000);

TRUNCATE TABLE test_insert_0_index;
INSERT INTO test_insert_0_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;  

TRUNCATE TABLE test_insert_1_index;
INSERT INTO test_insert_1_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_2_index;
INSERT INTO test_insert_2_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_3_index;
INSERT INTO test_insert_3_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_4_index;
INSERT INTO test_insert_4_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_5_index;
INSERT INTO test_insert_5_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_6_index;
INSERT INTO test_insert_6_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_7_index;
INSERT INTO test_insert_7_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_8_index;
INSERT INTO test_insert_8_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_9_index;
INSERT INTO test_insert_9_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;

TRUNCATE TABLE test_insert_10_index;
INSERT INTO test_insert_10_index (name, name1, name2, name3, name4, name5, name6, name7, name8, name9) SELECT name, name1, name2, name3, name4, name5, name6, name7, name8, name9 FROM test_insert_src;