[Info-vax] VMS databases

[Neil Rieck]

On Sunday, November 19, 2023 at 1:39:35 PM UTC-5, David Jones wrote:
> On Sunday, November 19, 2023 at 12:37:17 PM UTC-5, Stephen Hoffman wrote: 
> > If you ask nicely, SQLite will defer the locking until the commit: 
> > 
> > https://sqlite.org/cgi/src/doc/begin-concurrent/doc/begin_concurrent.md 
> > 
> > Otherwise, SQLite picks a simpler approach to database locking, 
> > permitting one concurrent writer.
> "BEGIN CONCURRENT" is part of an experimental 'high concurrency' development 
> branch and is not in the mainline code published by SQLite.org. If you try it you just 
> get a syntax error. 
> 
> Use of WAL mode (write-ahead logging) can alleviate some of the concurrent write 
> issues. It wants to use shared memory to coordinate between processes, however, 
> posing an issue for databases residing on shared disks in a cluster.

I have only done a small amount of SQLite programming on OpenVMS. In fact, I suppose you could say that it was only at the evaluation level because after I ran into some obvious problems, I switched over to MySQL / MariaDB then never looked back.

Now that is not to say that this is a garbage product. Most Linux people know that SQLite is employed by  RPM/YUM/DNF to keep track of package dependencies.

As I understand it, SQLlite is also employed on most smart phones, and there are probably more of these in the world than laptops, desktops, towers and servers.

Neil Rieck
Waterloo, Ontario, Canada.
https://neilrieck.net