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.NET/ASP.NET/C#/VB.NET PDF Document SDKA connection pool is a pool of physical connections that can be reused across multiple client sessions. Instead of creating and destroying a connection each time the client needs one, we maintain a pool of connections. These connections are created typically once in the beginning (or on demand) and destroyed only when an application shutdown or an error occurs. Connection pooling enables multiple clients to share a small pool of pre-established connections, thus improving performance and scalability tremendously. In this way, for example, a pool of 50 to 100 physical database connections can be shared by 100, 500, 1,000, or more users. In a three-tier architecture, the connection pool is maintained by the application server. When an application requests a connection, the application server takes a connection from the pre-established pool, marks it as in use, and hands it over to the application. During the request, the application has effectively reserved (or checked out) this connection object. When the application closes a connection, the application server returns the connection back to the pool after clearing the connection state (it does not actually close the physical connection). barcode add in for word and excel 2013, barcode add in for excel free, how to make barcodes in excel, excel barcode generator freeware, how to print 2d barcode in excel, excel barcode add-in from tbarcode office, barcode generator excel 2010, barcode generator excel mac, barcode add in for word and excel 11.10 free download, print barcode in excel 2010,possible to pass parameters by reference; thus, the C code may access the memory managed by the runtime, and errors in memory layout may result in corrupted memory. For this reason, PInvoke code should be kept to the minimum and verified accurately to ensure that the execution state of the virtual machine is preserved. The declarative nature of the interface is of great help in this respect since the programmer has to check simply declarations and not interop code. Not all the values are marshalled as-is to native code; some values may require additional work from the runtime. Strings, for instance, have different memory representations between native and managed code. C strings are arrays of bytes that are null terminated, while runtime strings are .NET objects with a different layout. Also, function pointers are mediated by the runtime: the calling convention adopted by the CLR is not compatible with external conventions, so code stubs are generated that can be called by native code from managed code, and vice versa. There are two performance advantages to this approach: Since we maintain a pool of connections (instead of creating and destroying connections with each request), the overhead of establishing database connections goes down dramatically for the case of a large number of users Since the application reserves the connection only for the duration of the request, we don t waste connection resources when the application is idle (ie, between requests) This again translates directly to improved performance and scalability Note that this solution scales only if you can map the large number of end users to a much smaller number of actual database users On a popular website such as http://wwwamazoncom, the number of users can run into the millions; creating a connection pool for these many different users is not feasible. when he had a digital signature requirement. When users selected a check box and filled in their names, their digital signatures were to be treated legally as their real signatures. In order to audit the signing of the page, the HTML needed to be captured exactly as the user was seeing it and put it into the database. He scratched his head on this for a while, but then realized that because of the ViewState maintenance, he could call Render on the page when the postback occurred and the output would look just as it had to the users when they submitted it. He created a file with this markup, sent it into the document management system, and redirected the users to a page thanking them for signing away their first born.
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