I did do-release-update from 18.10 and my computer freeze after a couple minutes using gnome with the tracker-extract process, even though my computer has 8 Go of RAM and 4 Go of SWAP that all get fully used. I can log in and work with any other desktop environment and I won't have that problem. I found out that I can remove tracker-extract following the process described here, which is what I'm going to do, even though I would have like to have that feature working.
Any pointers ?
Tracker was not enabled in 18.10. But, now, in 19.04, it's on by default.
If you've upgraded from 18.10 to 19.04, and you have a lot of files by such as documents, movies, music, photographs, videos etc. it's possible that tracker may take a long time to index everything. Until tracker's done, you may experience heavy resource usage.
I suggest that immediately after you login, open the Settings > Search interface, leaving the topmost slider green move the slider to the left for Ubuntu Software, Passwords …, and Terminal. Then click on the cog wheel and disable search for most of the items which you feel have the most files.
Now, hopefully, tracker should be able to complete it's job because you've limited its scope. If that indeed happens, go back to the Settings > Search interface and enable something else and so on.
Edit: as pointed out by starkus in a comment, it maybe necessary to reset tracker by clearing out the existing database in case it has developed some problem such as corruption:
tracker reset --hard
will do the job but please run tracker --help reset to read about it first.
