Kbase P14699: How do I use -cache?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
11/19/2008 |
|
Status: Verified
GOAL:
How do I use -cache?
FACT(s) (Environment):
All Supported Operating Systems
Progress/OpenEdge Product Family
FIX:
Schema Cache File (-cache)filename
Operating System
and Syntax UNIX
Windows -cache filename
Use With Maximum Value Minimum Value Single-user Default Multi-user Default CC - - - -
filename
The pathname of a binary schema cache file.
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.
To perform database activities, the Progress client keeps a copy of the database schema called the schema cache in memory. By default, Progress creates the schema cache by reading the database schema stored in the database file. The time required to read the schema is usually 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, Progress 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 Progress statement SAVE CACHE. 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 on building and saving the schema cache file, see the Progress Programming Handbook.
If you specify Schema Cache File (-cache) when you connect to a database and the local schema is valid, Progress 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 Progress cannot read the file, Progress issues a warning message and reads the schema from the database.
NOTE: If you are generating the local binary schema cache, do not connect to the database using Trigger Location (-trig) and Schema Cache File (-cache) together.