LOCLIB Model

Applications using the c-tree Plus Local Library (LOCLIB) model can access local data directly from the hard disk like the Stand Alone model and logon as a client to one or more c-tree Servers, as in the client/server model. This model is especially popular on PC-based systems where speed and efficiency is gained by using the local drive in lieu of taking the network hit to access a c-tree Server. Temporary work files, extracted c-tree Server data, local database information, and special “on the fly” index files are typically candidates for local disk access.

A LOCLIB library is a merger of the c-tree Plus stand alone file I/O logic and c-tree Plus client communication logic into the same library. Applications linked with the combined library have the best of both worlds, being able to access a local disk and one or more c-tree Servers. The c-tree Plus database function API is the same for both channels of I/O. Applications simply invoke a “switch” function call to direct the focus of the next operation. An application may log on to any number of c-tree Servers at the same time.

Benefits

• Provides fast local data storage and retrieval without adding extra network traffic.
• Complete source code for LOCLIB Library included in your c-tree Plus package.
• Configure local disk access as single-user, single-user transaction processing, or multi-user access. Allows an easy upgrade path to c-tree Server operation. Simply move the data under the c-tree Server and change connections to upgrade. See “c-tree Server” for migration information.
• Applications can access data locally and/or log on to any number of c-tree Servers at the same time. Both stand-alone and client/server models are supported for the same application.
• With heterogeneous support, this model provides a unique way to port data between different architectures. An application may read data from one platform and write it to another. The communication layer handles all necessary byte flipping.
• Applications may “register” as many “c-tree” access channels to different databases as needed.
• Applications may instigate “switch c-tree” calls to indicate which data source to direct the I/O.

Consideration

• On multi-tasking operating systems, consider running a c-tree Server on the local machine instead of using the LOCLIB model. Although the LOCLIB model supports single-user transaction control, it does not support multi-user transaction control over the local data. Multi-user transaction control is supported by running a local c-tree Server.