Kbase 18926: .SHM File On VMS
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
16/10/2008 |
|
Status: Unverified
FACT(s) (Environment):
Progress 8.1A
VMS
FIX:
Prior to Progress 8.1A01, if the logical PRO$NOSHM was defined as 1, Progress would not create a disk backing store file with the name "<dbname>.SHM", rather it would only create a system global section for shared memory when starting a server for a database.
Starting with Progress 8.1A01, this will now become the default.
That is, by default when starting a database server, the <dbname>.SHM file will not be created.
The reason for the change is purely performance related.
Keeping the .SHM file around means there is an extra write to the disk. Allowing shared memory to exist "only" in real memory means much faster access to the shared data by servers and clients.
To revert to prior functionality, define the following logical in the system startup procedures:
$ DEFINE /SYSTEM PRO$KEEP_SHM 1