Plan to make a new, blank tree & import your backup.
This will pack, re-index and switch to the SQLite database engine instead of staying with BSDDB.
Do not include Media in the 3.4.9 export into Gramps format. This feature gives you a false sense of security. Only media 1MB or smaller are included. It also makes the backup file larger & slower.
Write down the filename & filepath of the backup made in 3.4.9-1 version.
You’ll need to find it when you import.)
Copy that backup file to an external drive.
Also note your Base path for relative media paths
Read what is missing from a backup. Make plans to migrate any pieces critical to your use. (Such as: Did you have custom Report Books? Did you write Custom Filters?)
After installing Gramps 5.1.3 but before creating a new tree…
Tweak Preferences that will affect your import.
- Change the default ID formats. For example, 4 leading zeroes is not enough if you have more than 9,999 of any object. It still works but does not sort well in all cases. Changing Person (individuals) from I%04d to I%06d sorts up to 999,999 indexed individuals.
- Verify the Family Tree database backend is set to SQLite
- Turn OFF add tag on import (It is redundant for the 1st import, slows processing and makes the database bigger.) Turn it back on after import. It is useful for finding data to be merged after further imports.
As a general suggestion, take advantage of Add-Ons. In particular, add the Themes and use the switches in its Themes Preferences tab and the built-in Display tab to include labels on various icons in the GUI. You won’t need the labels for long. But labels will help you become reoriented.
Finally, you will want to get an idea of what old habits to break and new features to exploit.
Review the What Was Once New covering the versions you’re skipping.