本站首页    管理页面    写新日志    退出


«August 2026»
日一二三四五六
1
2345678
9101112131415
16171819202122
23242526272829
3031


公告
暂无公告...

我的分类（专题）

日志更新

最新评论

留言板

链接


Blog信息
blog名称:
日志总数:1
评论数量:0
留言数量:0
访问次数:16960
建立时间:2005年1月11日




OLE DB Programmer's Reference
文章收藏

czguang 发表于 2005/1/11 15:35:16

转载自: ms-help://MS.MSDNQTR.2003FEB.2052/oledb/htm/olprcore_chapter19_8.htm OLE DB Programmer's Reference 500)this.width=500'> Overriding Provider Service Defaults The provider's registry value for OLEDB_SERVICES is returned as the default value for the DBPROP_INIT_OLEDBSERVICES initialization property on the data source object. As long as the registry entry exists, the provider's objects will be aggregated and the consumer can override the provider's default setting for enabled services by setting the DBPROP_INIT_OLEDBSERVICES property prior to initialization. To enable or disable a particular service, the consumer will usually get the current value of the DBPROP_INIT_OLEDBSERVICES property, set or clear the bit for the particular property to be enabled or disabled, and reset the property. DBPROP_INIT_OLEDBSERVICES can be set directly in OLE DB or in the connection string passed to ADO or IDataInitialize::GetDatasource. Performance can be tuned using DBPROPVAL_OS_AGR_AFTERSESSION. When off, aggregation beyond the session level is disabled, resulting in improved performance. The setting is ignored when non–session level services, such as the Client Cursor Engine, are used. The corresponding values to enable or disable individual services are listed in the following tables. Note that the Client Cursor Engine is excluded; ADO invokes the Client Cursor Engine independent of these OLE DB Services. Default services enabled DBPROP_INIT_OLEDBSERVICESproperty value All services (default) DBPROPVAL_OS_ENABLEALL All except pooling and automatic transaction enlistment (DBPROPVAL_OS_ENABLEALL & ~DBPROPVAL_OS_TXNENLISTMENT & ~DBPROPVAL_OS_RESOURCEPOOLING) All except pooling (DBPROPVAL_OS_ENABLEALL &~DBPROPVAL_OS_RESOURCEPOOLING) All except automatic transaction enlistment (DBPROPVAL_OS_ENABLEALL &~DBPROPVAL_OS_TXNENLISTMENT) All except Client Cursor Engine (DBPROPVAL_OS_ENABLEALL & ~DBPROPVAL_OS_CLIENTCURSOR) All except pooling, automatic transaction enlistment, and Client Cursor Engine (DBPROPVAL_OS_ENABLEALL & ~DBPROPVAL_OS_RESOURCEPOOLING & ~DBPROPVAL_OS_TXNENLISTMENT & ~DBPROPVAL_OS_CLIENTCURSOR) Pooling and automatic transaction enlistment only, session level aggregation only DBPROPVAL_OS_TXNENLISTMENT & DBPROPVAL_OS_RESOURCEPOOLING No services DBPROPVAL_OS_DISABLEALL Default services enabled Value in connection string All services (default) "OLE DB Services = -1;" All except pooling and automatic transaction enlistment "OLE DB Services = -4;" All except Client Cursor Engine "OLE DB Services = -5;" All except pooling, automatic transaction enlistment, and Client Cursor Engine "OLE DB Services = -8;" Pooling and automatic transaction enlistment only, session level aggregation only "OLE DB Services = 3;" No services "OLE DB Services = 0;" Note   If the registry entry does not exist for the provider, the Component Managers will not aggregate the provider's objects and no services will be enabled, even if explicitly requested by the consumer. © 1998-2003 Microsoft Corporation. All rights reserved.


阅读全文(1761) | 回复(0) | 编辑 | 精华
 



发表评论：
昵称：
密码：
主页：
标题：
验证码：  (不区分大小写,请仔细填写,输错需重写评论内容！)



站点首页 | 联系我们 | 博客注册 | 博客登陆

Sponsored By W3CHINA
W3CHINA Blog 0.8 Processed in 0.014 second(s), page refreshed 144863617 times.
《全国人大常委会关于维护互联网安全的决定》  《计算机信息网络国际联网安全保护管理办法》
苏ICP备05006046号