Options for connecting to data server databases
You need to take many considerations into account when determining the most suitable connection method for your environment.
- A system that runs business applications on a business user's system or on an application server.
- An application development workstation.
- A database administrator workstation.
- On same system, that is, on the local system, such as databases in a single instance or in various instances.
- On different servers, such as on remote systems.
- On different servers that are midrange or mainframe servers.
Options for business user systems or application servers
Typically, when a business application connects to a database, one of the following topologies is involved:
- An application connects to a database where both are on the same server. An example is an application used by a single user on their personal workstation.
- An application connects to a database on another server.
- An application client connects to an application server which, in turn, connects to one or more
- On the same server only.
- On one or more servers.
- A combination of the preceding locations.
If a data server is installed on the same server as the application, there is no need to install a separate client. The data server includes functions to enable applications to connect to local databases and to connect to databases on remote servers, as well.
- Application driver. With an application driver, the information needed to connect to a database is included in the application or the application prompts the user to provide it. This approach differs from an IBM® data server client which maintains this information in its catalog. The application driver is deployed as a file in the application directory so no separate database server specific installation or setup is required. Typically, an application driver is packaged with an application in a manner that provides connectivity only for that application. A application driver can coexist on the same server with other application drivers or with an IBM data server client. Products provide drivers for Java™ (JDBC and SQLJ) and for ODBC, CLI, .NET, OLE DB, or open source applications. Drivers can be obtained by copying driver files from an IBM Data Server Driver Package installation image or by downloading the driver files from developerWorks®.
- IBM data server client. This option involves installing and configuring one of the clients included with the product. It is installed on any server that connects directly to the database. Depending on the application topology, the client is installed on each business user workstation or on an application server. A single client can enable all applications on the server to connect to one or more databases on other machines.
- Instance merge modules. These merge modules create an instance environment. This approach provides a way to deploy the IBM Data Server Runtime Client by including the files in the corresponding modules. This approach is targeted for use with Windows Installer and other installation tools that support Windows Installer merge modules. With this approach, a single installation program installs both the application and the data server runtime client. If you do not require an instance environment or a command line processor (CLP), then use a secondary type of instance merge modules to avoid instance management.
- Other instance merge modules. These merge modules create an instance environment in database other than Db2®. This approach provides a way to deploy the IBM Data Server Driver Package by including the client DLL files in the application deployment package. This approach is targeted for use with Windows Installer and other installation tools that support Windows Installer merge modules. With this approach, a single installation program installs both the application and the data server driver package.
Options for application development workstations
The IBM Data Server Client provides all the functions of the IBM Data Server Runtime Client plus tools used for client-server configuration, database administration, and application development. The following points describe the role and setup in light of the other tools and products used by application developers.
There are several tools and products typically used by application developers who write code to access a database. Each developer workstation typically includes the following components:
- An integrated development environment (IDE) such as IBM Data Studio, IBM Optim™ Development Studio, Rational® Application Developer or Microsoft Visual Studio.
- A specific development tool related to the IDE such as IBM Database Add-ins for Microsoft Visual Studio.
- Access to a database server to host the database they are developing.
This database server can be in one or both of the following locations:
- On each developer's workstation, so each developer has their own local copy of the database.
- On a workgroup server, so multiple developers work on the same copy of the database.
With the foregoing as context, the value of the Data Server Client is that it provides headers and libraries required to compile applications and provides tools for database administration. However, it is not always necessary to install it to obtain these tools. Any time a data server is installed, there is no need to install a separate IBM data server client. The data server includes all functions available in a stand-alone data server client.
Options for administrator workstations
A database administrator can administer tasks on remote databases in one of two major ways. They use a tool, such as telnet, to connect to an individual database server machine and run administrator commands locally. Alternatively, they can run tools and commands from their workstation that make connections to the remote databases. This section focuses on the second case which involves choices about which IBM data server client to use and where to install it.
- Install the IBM Data Server Runtime Client. This option is suitable if you use the command line processor (CLP) for administration.
- Install the IBM Data Server Client. This client includes all the functions of the Data Server Runtime Client plus tools used for client-server configuration, database administration, and application development. Functions include the graphical administration tools such as the InfoSphere® Optim Configuration Manager and IBM Data Studio (available on supported platforms). These tools use the Db2 Administration Server (DAS) on the data server, which is set up by default during the data server installation.
- Install a data server product. Any time a data server is installed on a server, there is no need to install a separate IBM data server client. The data server includes all the functions available in any stand-alone IBM data server client.
Options for connecting to midrange and mainframe databases
With Db2 Connect products, you can connect to databases on mainframe and midrange platforms, namely OS/390® and z/OS®, System i®, VSE, and VM. You can also connect to other databases that comply with the Distributed Relational Database Architecture™ (DRDA). With Db2 Connect, you can connect from a user's workstation or from a Db2 server.
- IBM Data Server Driver Package. This lightweight deployment solution that provides runtime support for applications using ODBC, CLI, .NET, OLE DB, PHP, Ruby, JDBC, or SQLJ without the need of installing Data Server Runtime Client or Data Server Client. To connect to a z/OS server or a System i server, you must register a Db2 Connect license key. (Retrieve the license file from your Passport Advantage® distribution, for example db2conpe.lic, then copy the license file to the license directory under the directory where the driver was installed.)
- Db2 Connect server Editions. A server edition of the Db2 Connect product is installed on a connectivity server and serves as a gateway to supported mainframe or midrange database servers. A server edition of the it enables workstations with IBM data server clients to setup access to host systems with the Db2 Connect gateway as if they were databases on Db2.
- Install Db2 Connect locally and use it to connect directly to a host.
- Connect to the same or different host through an intermediate Db2 Connect server gateway.