Gramps with PostgreSQL : multi-user use?

[105rn]

Hello,
I saw that it’s possible to work with a PostgreSQL database instead of SQLite.
Would this allow multi-user use on a local network?
If so, have any tests been done yet?
Thanks

[emyoulation]

The database backend is not where the Gramps (for desktops) single-user limitation is implemented.

See the discussion at

Should the Plugin Registration fail gracefully for missing Prerequisites?

Hopefully we can allow multi-user access to any backend. The reason for the single-user restriction was to improve the performance of the BSDDB database. If the _create_undo_manager approach doesn’t work then I am open to consider alternatives. It may also be time to have another look at storing objects as JSON rather than pickled blobs. I’ll release v5.2.1 over the weekend. After that, I’ll have time to start thinking about v5.3.

[105rn]

@emyoulation

The database backend is not where the Gramps (for desktops) single-user limitation is implemented.

Thank you!
So if I understand correctly, this isn’t a viable solution.

[emyoulation]

@105rn

So if I understand correctly, this [PostgreSQL or shared PostgreSQL] isn’t a viable solution [for multi-user access].

Correct. Gramps for Desktop intentionally implements a lock file in the database folder to prohibit multi-user access.

There has been deliberate movement towards identifying and resolving the roadblocks for multi-user access.

[Nick-Hall]

@105rn

Would this allow multi-user use on a local network?
If so, have any tests been done yet?

Concurrent access is possible on a local network, but not yet supported. There are a few issues to be aware of:

• If two users edit the same object at the same time, the last record object will overwrite previous changes.
• The undo facility will undo the last local change, which may not be the last change made.
• Metadata is not written to the database immediately. This is actually a bug that needs fixing and will also cause a problem in single-user mode if Gramps crashes.

For testing purposes you can just delete the lock file as @emyoulation mentioned. The SQLite backend also supports multi-user access.

One of our goals is to support concurrent access on the Gramps desktop. For true multi-user access Gramps Web is a more suitable solution.

[emyoulation]

@Nick-Hall

Metadata is not written to the database immediately. This is actually a bug that needs fixing and will also cause a problem in single-user mode if Gramps crashes.

Thanks for that info.

Found the bug report for metadata:

0013721: Missing metadata when Gramps crashes before a new database is closed...

Where is the documentaion on what constitutes the metadata that is at risk?

[105rn]

Thank you all!!
If this isn’t viable, I’ll refrain from taking any risks.
Bertrand

[glamberson]

Hi, Your PostgreSQL topic caught my eye. While I understand concurrency isn’t only a database issue for GRAMPS, I do need a more robust postgres option for work I’m doing. Thus I’m about to publish a very alpha version of a postgres addon with psycopg3 and many more modern features. I hope you’ll check it out and give me feedback, but keep in mind it’s a very new extension so I wouldn’t rely on it.

Thanks,

Greg Lamberson

[105rn]

@glamberson

PostgreSQL

Hi,
I was actually wondering if Gramps wasn’t multi-user because of SQLite… and that’s not the only reason.
PostgreSQL is known to be more robust but also more difficult to install.
So I’ll be looking at this new add-on with interest.
Bertrand