Database data file backward compatibility?

I want to share one data file among older and newer Macs and Windows computers running different versions of LibreOffice. I know older LibreBase datafiles can be opened with later versions of base, but don’t know if they can be opened or modified with later versions of LibreBase and remain modifiable by the original version. Specifically, can a datafile created using LibreBase 3.6.1 on an older Mac be opened, read and modified by LibreBase 6.X.X on a later Mac and the resultant file still be read and modified by LibreBase 3.6.1 on the original older Mac?

Are you asking with regard to ODB files with embedded database (HSQL) specifically?

I am referring to the type of ODB files that are created when you use the Wizard. I don’t know if these have embedded database or not, since I am a first time user who has not studied LibreOffice files enough to understand your question.

Well, you started by saying you had one file to share. So if you open that one file today in the status bar, the bottom of screen, does it have the word HSQL somewhere? If so that is what you have.

Yes, it reads “HSQLDB Embedded”

Yes and NO

A Base file, the OpenDocument Database Frontend .odb file, is compatible across all of the versions.

If the file is using an external datasource (via jdbc or obdc connector) then as long as all the machines can see the datasource then they are easily shared and still compatible across all versions of LibreOffice (LO).

If the .odb file is using an embedded database and that database is HSQL engine based, (the default until recently) then the file is compatible across all versions of LO today. However the embedded HSQL support is slated to be removed. At that point the older files would not usable on the latest LibreOffice (perhaps sometime next year 2020 perhaps later).

Today you can also create a Base file with an embedded Firebird database, this will become the only option for an embedded engine when HSQL is dropped.

The support for Firebird embedded odb files has been added to the package over the last half dozen release cycles. There are some features lacking in earlier releases, particularly with regards to data table design, available in more recent LibreOffice releases, but the files created in the newer LO versions are runtime compatible for data entry (don’t try to use the table design features in the older workstations) with older LO versions 5.x line.

So in your case, where you are talking about versions of LibreOffice running from 3.6 through 6.x this single file, which is likely using the HSQL data engine, will work for the near term, but there will come a point where that will no longer be the case. To stay with an embedded database file shared between the workstations you would have to move the data to Firebird internally and that would require the older stations to be upgraded to at least LibreOffice 5.x.

Thank you for your very complete answer! It gives me enough confidence to start adding data to a database created with the older version knowing it can be converted to Firebird when necessary.