Kbase 17034: What is a Schema Holder For an AS/400 Database
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/16/2008 |
|
Status: Verified
GOAL:
What is a Schema Holder For an AS/400 Database
FACT(s) (Environment):
Progress/400 DataServer
FIX:
A Schema Holder is a Progress database that contains the client's information about the DB2/400 files that are used in conjunction with the AS/400 Server Schema on the AS/400 to access the corresponding DB2/400 data.
The Progress/400 DataServer uses the Schema Holder to map the data definitions in the Server Schema to a format that Progress can understand.
The Schema Holder contains a series of hidden tables with a prefix (p__) that corresponds to Progress metaschema files.
All changes to the client schema holder are made through a synchronization process. This process refreshes the image from the updated definitions in the Server Schema. This process is in the DataServer->DB2/400 Utilities.
The synchronization performs the following:
- checks Server Schema file timestamps on logical files and the record format level on physical files to see which file definitions have changed;
- applies file definition changes to the corresponding client Schema Holder files.