[Info-vax] SQLite and vmsvfs

[osuvman50 at gmail.com]

On Thursday, October 27, 2016 at 9:40:52 PM UTC-4, Marty wrote:
> I've been looking at the latest SQLite version for VMS (3.14.1) the last few days and saw there were notes about VMSvfs.  I'm assuming this is a virtual file system that helps out SQLite, but have not found any useful information about what VMSvfs is all about.
> 

VFS in this context is the layer in the SQLite code that provides the interface between the operating system for file operations and the rest of SQLite.  http://sqlite.org/vfs.html has a good description of it.  Note that VFS isn't strictly file system functions, it also has some other operations that tend to be OS-specific.

The main thing the VMSvfs module does is provide a better fullpathname() function and file locking functions.  Most of the functions just call the method in the unix vfs where CRTL provides adequate compatibility.  You can configure SQLite to use the straight unix vfs when it initializes, but don't try to share the database.