----------------------------------------------------------- New Message on MumbaiUserGroup
----------------------------------------------------------- From: aamirOnline Message 3 in Discussion Hi 1) How do you achieve concurrency control in a vb.net application Are you talking about ADO.Net data concurrency or Threading (Threadsafty) ? 2) When would you use datareader and when would you use a dataset Dataset uses IDataAdapter which further uses uses IDbCommand and IDbDataReader for CRUD (Create Read Update Delete) operations.... Dataset is said to be an in memory representation of the database means, it can load and hold multiple database tables and their relationships for disconnected data processing which demands more memory on the server. whereas datareader doesnt hold the records in the momory so less memory is required. CRUD is faster in connected scenario (IDbCommand and IDataReader) where as its slow in the Disconnected scenario becase of intermediate processings. But Datasets give you more power more control where as DataReader doesnt...... According to MSDN when deciding whether your application should use a DataReader (see Retrieving Data Using the DataReader) or a DataSet (see Creating and Using DataSets), you should consider the type of functionality that your application requires. Use a DataSet to do the following: Remote data between tiers or from an XML Web service. Interact with data dynamically such as binding to a Windows Forms control or combining and relating data from multiple sources. Cache data locally in your application. Provide a hierarchical XML view of relational data and use tools like an XSL Transformation or an XML Path Language (XPath) Query on your data. For more information, see XML and the DataSet. Perform extensive processing on data without requiring an open connection to the data source, which frees the connection to be used by other clients. If you do not require the functionality provided by the DataSet, you can improve the performance of your application by using the DataReader to return your data in a forward-only read-only fashion. Although the DataAdapter uses the DataReader to fill the contents of a DataSet (see Populating a DataSet from a DataAdapter), by using the DataReader you can receive performance gains because you will save memory that would be consumed by the DataSet, as well as saving the processing required to create and fill the contents of the DataSet. Hope you got the answer..... regards M Aamir Maniar System Analyst (CWS), Freelance OOAD Consultant [EMAIL PROTECTED] ----------------------------------------------------------- To stop getting this e-mail, or change how often it arrives, go to your E-mail Settings. http://groups.msn.com/mumbaiusergroup/_emailsettings.msnw Need help? If you've forgotten your password, please go to Passport Member Services. http://groups.msn.com/_passportredir.msnw?ppmprop=help For other questions or feedback, go to our Contact Us page. http://groups.msn.com/contact If you do not want to receive future e-mail from this MSN group, or if you received this message by mistake, please click the "Remove" link below. On the pre-addressed e-mail message that opens, simply click "Send". Your e-mail address will be deleted from this group's mailing list. mailto:[EMAIL PROTECTED]
