Single-Tier (Lite Edition)

UDA (ODBC, JDBC, ADO.NET, OLE-DB, XMLA) > OLEDB Data Providers > Single-Tier (Lite Edition)

What are Single-Tier Drivers?

OpenLink Single-Tier Drivers are a single component installed on a data-consuming machine (a client in a client/server architecture, or on an application-server machine, according to architecture).

Why is it important?

Being installed only on the client machine, the OpenLink Single-Tier endeavours to make the job for developers, administrators and end-users simpler. By discarding the Server-side setup, there is no server-side administration so the user is provided with a single entry-point for installation and administration. In the majority of cases, knowing the database is all that is required. To the developer writing an application, there is no requirement to know on which server it resides: you can write your application for any environment, regardless of where it will end. There are also performance benefits gained by employing this single solution, which in some cases exceeds that provided by the native drivers. Being able to integrate your solution simply into your organization with its plethora of internal and disparate systems means your return-on-investment increases significantly.

Driver Architecture

These drivers are built by implementing the OLEDB data-access interface specifications using a database-vendor-provided Call Level Interface (CLI). Thus, the capabilities and architecture of the CLI significantly affect the functional outcome of a driver.

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OLEDB and any other data-access drivers for that matter, are developed using the call-level interface (CLI) of the respective databases that they support. These call level interfaces take the following forms:

Type A - C-based dynamic SQL interface including client and server networking components
Type B - C-based remote procedure calls (RPC) interface to the wire-protocol of the underlying database. This is a client-only interface that communicates directly with the remote database server. These interfaces arent typically available to third-party developers. To date the Open Source projects such as FreeTDS, MySQL, PostgreSQL, and Interbase are the only publicly accessible and freely available versions of such interfaces.
Type C - Generic bridges: these are OLE DB providers that act as implementation proxies, such that bridging can be achieved in the manner depicted in the matrix below:

OpenLink provides Single-Tier Drivers built using the Type A, B, and C call-level interfaces formats, depending on what is publicly available to third-party developers by the vendors of the respective database engines.

Please view your respective Data Access Mechanism for more information.

Single-Tier Architectural Diagram

OpenLink Single-Tier Drivers provide developers or users with OleDB access to remote or local databases, and on a wider variety of operating systems. With the OpenLink drivers, technologies such as Microsoft Data Transformation Services (DTS) can be used to access and transform disparate database technologies running on remote systems that might not have been possible before.

The OpenLink OLEDB provider for ODBC is an OLEDB-ODBC Bridge provider, written in C++, exploiting ODBC to enable connectivity to an ODBC-compliant DSN (database).

If the underlying ODBC driver is the OpenLink driver, the possible driver-types depend on what is made publicly available by the vendors of the respective database engines. Below are architectural diagrams showing the different type representations for the OLE-DB drivers available.

Type A CLI-based Single-Tier Drivers

These drivers are built using the Type-A call-level interfaces of the relevant back-end database engine. Thus, these drivers implement the interfaces of the respective data-access mechanisms (ODBC) with inherent database-specific networking, and a dependency on the database vendor-provided networking middleware products. At installation time you simply install the driver with the underlying assumption that remote database connectivity is already in place (or will be put in place) via the installation of products such as Net8 and SQL*Net, Progress Client Networking, Informix Connect, Ingres Net, DB/2 Connect etc.

Type-A Architectural Diagram for OLE-DB Image scaled down; Click to enlarge.

Single-Tier Type-A OLE-DB Driver for Progress

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Type-B CLI based Single-Tier Drivers

These drivers are built using the Type-B client-networking interface to wire-protocols of the supported back-end database. These drivers are installed once on a workstation/desktop or application server machine, and after installation are ready for direct communication with the supported backed database. The driver format is only currently available for Microsoft SQL Server, SYBASE ASE, MySQL, PostgreSQL, and OpenLink Virtuoso. Support for other databases will occur as and when unsupported database engine vendors make their RPC client interfaces available to third party developers.

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Type-C CLI based Single-Tier Drivers

These drivers are proxies that sit atop third-party implementations of the relevant data-access mechanisms (ODBC, JDBC etc). The prime purpose is to integrate one data-access standard implementation with another. There are a variety of scenarios where this is useful such as: