Three-tier database and application Server clarification facts

Everyone is not very familiar with the application server, so take my understanding.

Application server addresses two major issues

In a client/server mode: The database server is responsible for connection problems (brother Xiang Yu has met)

Two Web site to dynamically update data and database to Internet connection problem

There are other aspects of the application not to say.

The first mode application environment is mainly in the LAN: Client program + Application Server + database

Second mode application in the Internet: Browser +web server + Application Server + database

The local area network can adopt the browser, the Internet can also customer program.

Can imagine a local area network can be large data flow, the Internet must be small data flow.

Where is the rule applied?

After using the application server, everyone reached a consensus on the rules on the client.

Some people put the rules in the application server, can reduce the workload of the database.

I think the rule is to let the database to manage, the database ability is stronger than us.

Only some very old database management rules are very low, perhaps not relational database

The application server has to deal with the rules.

The application server is best responsible for connection, data traffic monitoring, providing quality services to the client,

Better compatible with different types of, old-fashioned databases.

There are currently three types of application servers

The decentralized type of Microsoft: spread to different technologies.

Database vendors: When they sell the database, they sell the application server (private).

Independent software vendor: a stand-alone application server developed.

Suitable for different situations.

And we, I think, are developing an independent application server that provides better flexibility and compatibility.

We will pay attention to the future when we develop.

C++BUILDER5 provides us with a variety of parts for developing client and application servers.

Application server-side parts: Tdatasetprovider+bde mode parts (Table,query ...) +ado (Adotable ...). ODBC or through the BDE parts; SQL link I haven't even seen it.

ADO parts are not rich without BDE sessions, bulk moving, cache updates, nested tables, and no interbase transactions, database information, monitoring, events.

BDE released when the complex is very, very disobedient, even if the installation procedures are embarrassing. Hope C++BUILDER6 can enhance ADO function, ah Deiphl6 out of the noncommittal?

Client

Tdatasource+tclientdataset+{tdcomconnection; Tsocketconnection; Twebconnection; Tcorbaconnction; Tsimpleobjectbroker}