Use Schema Cache File (-cache) to read the database schema from a local file instead of the database. You must have previously built the schema cache and stored it as a binary file.

filename

The pathname of a binary schema cache file.

To perform database activities, the OpenEdge client keeps a copy of the database schema called the schema cache in memory. By default, OpenEdge creates the schema cache by reading the database schema stored in the database file. The time required to read the schema usually is minimal; however, under the following conditions, the time required to read the schema might be unacceptable:

• If the client connects to the database over a wide-area network (WAN)
• When a large number of clients connect to a database simultaneously, for example, after a database shutdown or crash

Connection time depends on several factors, including schema size.

To reduce connection time, OpenEdge lets you store the schema cache as a binary file, called a schema cache file, on a local disk. The client can then read the schema directly from the schema cache file.

To write the schema cache file, you build the desired schema cache and save it to a binary file using the ABL SAVE CACHE statement. The schema cache file is portable across systems, so you can create the file once and distribute it across a heterogeneous network of systems. For information about building and saving the schema cache file, see OpenEdge Programming Interfaces.

If you specify schema cache file (-cache) when you connect to a database and the local schema is valid, the AVM reads the schema from the local file instead of from the database. The schema cache is valid if the time stamp of the schema cache file matches the time stamp in the database master block. If the time stamps do not match, or for some reason the AVM cannot read the file, the AVM issues a warning message and reads the schema from the database.