【IT168 技术文档】
MySQL支持的两种主要表存储格式MyISAM,InnoDB,上个月做个项目时,先使用了InnoDB,结果速度特别慢,1秒钟只能插入10几条。后来换成MyISAM格式,一秒钟插入上万条。当时觉的这两个表的性能也差别太大了吧。后来自己推测,不应该差别这么慢,估计是写的插入语句有问题,决定做个测试:
测试环境:Redhat Linux9,4CPU,内存2G,MySQL版本为4.1.6-gamma-standard
测试程序:Python+Python-MySQL模块。
测试方案:
1、MyISAM格式分别测试,事务和不用事务两种情况:
2、InnoDB格式分别测试AutoCommit=1(不用begin transaction和用begin transaction模式),
AutoCommit=0 (不用begin transaction和用begin transaction模式)四种情况。
测试方法为插入10000条记录。为了测试不互相影响,单独建立了专用的测试表,建表语句如下:
1、MyISAM不用事务表:
CREATE TABLE `MyISAM_NT` ( `TableId` int(11) NOT NULL default '0', `TableString` varchar(21) NOT NULL default '' ) ENGINE=MyISAM;
2、MyISAM用事务表:
CREATE TABLE `MyISAM_TS` ( `TableId` int(11) NOT NULL default '0', `TableString` varchar(21) NOT NULL default '' ) ENGINE=MyISAM;
3、InnoDB关闭AutoCommit,不用事务:
CREATE TABLE `INNODB_NA_NB` ( `TableId` int(11) NOT NULL default '0', `TableString` varchar(21) NOT NULL default '' ) ENGINE=InnoDB;
4、InnoDB关闭AutoCommit,用事务:
CREATE TABLE `INNODB_NA_BE` ( `TableId` int(11) NOT NULL default '0', `TableString` varchar(21) NOT NULL default '' ) ENGINE=InnoDB;
5、InnoDB开启AutoCommit,不用事务:
CREATE TABLE `INNODB_AU_NB` ( `TableId` int(11) NOT NULL default '0', `TableString` varchar(21) NOT NULL default '' ) ENGINE=InnoDB;
6、InnoDB开启AutoCommit,用事务:
CREATE TABLE `INNODB_AU_BE` ( `TableId` int(11) NOT NULL default '0', `TableString` varchar(21) NOT NULL default '' ) ENGINE=InnoDB;
测试的Python脚本如下:
#!/usr/bin/env Python ''' MyISAM,InnoDB性能比较 作者:空心菜(Invalid) 时间:2004-10-22 ''' import MySQLdb import sys import os import string import time c = None testtables = [("MyISAM_NT",None,0), ("MyISAM_TS",None,1), ("INNODB_NA_NB",0,0), ("INNODB_NA_BE",0,1), ("INNODB_AU_NB",1,0), ("INNODB_AU_BE",1,1) ] def BeginTrans(): print "ExecSQL:BEGIN;" c.execute("BEGIN;") return def Commit(): print "ExecSQL:COMMIT;" c.execute("COMMIT;") return def AutoCommit(flag): print "ExecSQL:Set AUTOCOMMIT = "+str(flag) c.execute("Set AUTOCOMMIT = "+str(flag)) return def getcount(table): #print "ExecSQL:select count(*) from "+table c.execute("select count(*) from "+table) return c.fetchall()[0][0] def AddTable (Table,TableId,TableString): sql = "INSERT INTO "+Table+"(TableId, TableString) VALUES( "+ TableId+ ",'" + TableString +"')" try: c.execute(sql) except MySQLdb.OperationalError,error: print "AddTable Error:",error return -1; return c.rowcount def main(): argv = sys.argv if len(argv) < 2: print 'Usage:',argv[0],' TableId TestCount \n' sys.exit(1) global c #mysql访问cursor db_host = "localhost" db_name = "demo" db_user = "root" db_user_passwd = "" print "Config:[%s %s/%s %s] DB\n"%(db_host,db_user,db_user_passwd,db_name) if len(argv) > 2: tableid = argv[1] testcount = int(argv[2]) # for test in testtables: #每次操作前都重写建立数据库连接 try: mdb = MySQLdb.connect(db_host, db_user, db_user_passwd, db_name) except MySQLDb.OperationalError,error: print "Connect Mysql[%s %s/%s %s] DB Error:"%(db_host,db_user,db_user_passwd,db_name),error,"\n" sys.exit(1) else: c = mdb.cursor() table,autocommit,trans = test starttime = time.time() print table," ",time.strftime("%y-%m-%d %H:%M:%S",time.localtime()) if autocommit != None: AutoCommit(autocommit) if trans == 1: BeginTrans() for i in xrange(testcount): tablestring = "%020d"%i if (AddTable(table,tableid,tablestring)<1): print "AddTable Error",tablestring if trans == 1: Commit() print time.strftime("%y-%m-%d %H:%M:%S",time.localtime()) endtime = time.time() usedtime = endtime-starttime print table,"count:",getcount(table)," used time:",usedtime c.close() mdb.close() if __name__ == '__main__': main()
测试结果如下:
Config:[localhost root/ demo] DB MyISAM_NT 04-10-22 16:33:24 04-10-22 16:33:26 MyISAM_NT count: 10000 used time: 2.1132440567 MyISAM_TS 04-10-22 16:33:26 ExecSQL:BEGIN; ExecSQL:COMMIT; 04-10-22 16:33:29 MyISAM_TS count: 10000 used time: 2.65475201607 INNODB_NA_NB 04-10-22 16:33:29 ExecSQL:Set AUTOCOMMIT = 0 04-10-22 16:33:31 INNODB_NA_NB count: 10000 used time: 2.51947999001 INNODB_NA_BE 04-10-22 16:33:31 ExecSQL:Set AUTOCOMMIT = 0 ExecSQL:BEGIN; ExecSQL:COMMIT; 04-10-22 16:33:35 INNODB_NA_BE count: 10000 used time: 3.85625100136 INNODB_AU_NB 04-10-22 16:33:35 ExecSQL:Set AUTOCOMMIT = 1 04-10-22 16:34:19 INNODB_AU_NB count: 10000 used time: 43.7153041363 INNODB_AU_BE 04-10-22 16:34:19 ExecSQL:Set AUTOCOMMIT = 1 ExecSQL:BEGIN; ExecSQL:COMMIT; 04-10-22 16:34:22 INNODB_AU_BE count: 10000 used time: 3.14328193665
结论
由此得知影响速度的主要原因是AUTOCOMMIT默认设置是打开的,我当时的程序没有显式调用BEGIN;开始事务,导致每插入一条都自动Commit,严重影响了速度。