(1)MySQLdb 是用于Python连接Mysql数据库的接口,它实现了 Python 数据库 API 规范 V2.0,基于 MySQL C API 上建立的。除了MySQLdb外,python还可以通过oursql,PyMySQL, myconnpy等模块实现MySQL数据库操作;
(2)DBUtil中提供了几种连接池,用以提高数据库的访问性能,例如PooledDB,PesistentDB等
(3)sqlobject可以实现数据库ORM映射的第三方模块,可以以对象、实例的方式轻松操作数据库中记录。
为测试这三者的性能,简单做一个例子:50个并发访问4000条记录的单表,数据库记录如下:
测试代码如下:
1、MySQLdb的代码如下,其中在connDB()中把连接池相关代码暂时做了一个注释,去掉这个注释既可以使用连接池来创建数据库连接:
(1)DBOperator.py
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import MySQLdb from stockmining.stocks.setting import LoggerFactory import connectionpool class DBOperator( object ): def __init__( self ): self .logger = LoggerFactory.getLogger( 'DBOperator' ) self .conn = None def connDB( self ): self .conn = MySQLdb.connect(host = "127.0.0.1" ,user = "root" ,passwd = "root" ,db = "pystock" ,port = 3307 ,charset = "utf8" ) #当需要使用连接池的时候开启 #self.conn=connectionpool.pool.connection() return self .conn def closeDB( self ): if ( self .conn ! = None ): self .conn.close() def execute( self , sql): try : if ( self .conn ! = None ): cursor = self .conn.cursor() else : raise MySQLdb.Error( 'No connection' ) n = cursor.execute(sql) return n except MySQLdb.Error,e: self .logger.error( "Mysql Error %d: %s" % (e.args[ 0 ], e.args[ 1 ])) def findBySQL( self , sql): try : if ( self .conn ! = None ): cursor = self .conn.cursor() else : raise MySQLdb.Error( 'No connection' ) cursor.execute(sql) rows = cursor.fetchall() return rows except MySQLdb.Error,e: self .logger.error( "Mysql Error %d: %s" % (e.args[ 0 ], e.args[ 1 ])) |
(2)测试代码testMysql.py,做了50个并发,对获取到的数据库记录做了个简单遍历。
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import threading import time import DBOperator def run(): operator = DBOperator() operator.connDB() starttime = time.time() sql = "select * from stock_cash_tencent" peeps = operator.findBySQL(sql) for r in peeps: pass operator.closeDB() endtime = time.time() diff = (endtime - starttime) * 1000 print diff def test(): for i in range ( 50 ): threading.Thread(target = run).start() time.sleep( 1 ) if __name__ = = '__main__' : test() |
2、连接池相关代码:
(1)connectionpool.py
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from DBUtils import PooledDB import MySQLdb import string maxconn = 30 #最大连接数 mincached = 10 #最小空闲连接 maxcached = 20 #最大空闲连接 maxshared = 30 #最大共享连接 connstring = "root#root#127.0.0.1#3307#pystock#utf8" #数据库地址 dbtype = "mysql" def createConnectionPool(connstring, dbtype): db_conn = connstring.split( "#" ); if dbtype = = 'mysql' : try : pool = PooledDB.PooledDB(MySQLdb, user = db_conn[ 0 ],passwd = db_conn[ 1 ],host = db_conn[ 2 ],port = string.atoi(db_conn[ 3 ]),db = db_conn[ 4 ],charset = db_conn[ 5 ], mincached = mincached,maxcached = maxcached,maxshared = maxshared,maxconnections = maxconn) return pool except Exception, e: raise Exception, 'conn datasource Excepts,%s!!!(%s).' % (db_conn[ 2 ], str (e)) return None pool = createConnectionPool(connstring, dbtype) |
3、sqlobject相关代码
(1)connection.py
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from sqlobject.mysql import builder conn = builder()(user = 'root' , password = 'root' , host = '127.0.0.1' , db = 'pystock' , port = 3307 , charset = 'utf8' ) |
(2)StockCashTencent.py对应到数据库中的表,50个并发并作了一个简单的遍历。(实际上,如果不做遍历,只做count()计算,sqlobject性能是相当高的。)
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import sqlobject import time from connection import conn import threading class StockCashTencent(sqlobject.SQLObject): _connection = conn code = sqlobject.StringCol() name = sqlobject.StringCol() date = sqlobject.StringCol() main_in_cash = sqlobject.FloatCol() main_out_cash = sqlobject.FloatCol() main_net_cash = sqlobject.FloatCol() main_net_rate = sqlobject.FloatCol() private_in_cash = sqlobject.FloatCol() private_out_cash = sqlobject.FloatCol() private_net_cash = sqlobject.FloatCol() private_net_rate = sqlobject.FloatCol() total_cash = sqlobject.FloatCol() def test(): starttime = time.time() query = StockCashTencent.select( True ) for result in query: pass endtime = time.time() diff = (endtime - starttime) * 1000 print diff if __name__ = = '__main__' : for i in range ( 50 ): threading.Thread(target = test).start() time.sleep( 1 ) |
测试结果如下:
MySQLdb平均(毫秒) | 99.63999271 |
DBUtil平均(毫秒) | 97.07998276 |
sqlobject平均(毫秒) | 343.2999897 |
结论:其实就测试数据而言,MySQLdb单连接和DBUtil连接池的性能并没有很大的区别(100个并发下也相差无几),相反sqlobject虽然具有的编程上的便利性,但是却带来性能上的巨大不足,在实际中使用哪个模块就要斟酌而定了。
(冯智杰:PMP、信息系统项目管理师,大型企业高级开发经理,关注金融、供应链行业发展,擅长敏捷开发、项目管理、技术研发等)