[Info-vax] VMS databases

[Jake Hamby (Solid State Jake)]

On Monday, November 20, 2023 at 6:17:41 PM UTC-8, David Jones wrote:
> On Monday, November 20, 2023 at 4:14:49 PM UTC-5, Arne Vajhøj wrote: 
> > On 11/20/2023 2:46 PM, Jake Hamby (Solid State Jake) wrote: 
> > > It’s also an unusual choice 
> > > to create a separate file for lock management and put it in the 
> > > user’s home directory. What if you want to make the database file 
> > > accessible to multiple users? 
> > Multi-users does not necessarily mean multiple usernames. 
> > 
> > But if multiple usernames then you can define the logical 
> > SQLITE3_NEXUS_FILE to point to a file shared among them. 
> >
> The VMS VFS supports 2 lock methods. The default is to use a nexus file, 
> which lets users run SQLite without requiring an administrator account to 
> set up. The alternate method uses system DLM locks accessed via a User 
> Written System Service (UWSS), which requires an administrator to 
> install the SQLITE3_PRV_LOCK protected image (usually at system startup).

Ah, that's interesting. My apologies for skipping over that option. I'll have to check out that code. User-written system services are an interesting concept.

Jake