Is it really true that Delete Old App Data will safely delete leftovers from Arc Timeline 3 and leave everything that migrated to Arc Timeline 4? According to the latter, the former amounts to 9.57GB, which is two-thirds of all Arc-related data.
I just want to reliably confirm that everything I ever had in version 3 has been so optimized that it uses 40% less space and I can still go back and make all the usual confirmations and updates to the metadata as I can with data recorded in version 4.
Otherwise, my intention remains to delete the version 3 app from my iPhone near the end of November when my current subscription expires and subscribe anew using version 4.
@earthsaver, yes. Delete Old App Data removes the databases the old app left in the shared container, the ones Arc Timeline 3 and Arc Recorder write to, and leaves Arc Timeline 4’s own database alone. The button stays locked while the migration check sees old-app history that hasn’t come across to Arc Timeline 4, and for an hour after anything last wrote to those databases; the footer under it says which. So with Arc Timeline 3 still recording it will sit greyed until you’re done with it.
File size isn’t a measure of what came across, so the 9.57 GB doesn’t tell you either way. The check that does: compare the earliest day in the Timeline tab’s calendar in both apps, and spot-check a few days you remember. Migrated items are ordinary Arc Timeline 4 items, so confirming, retyping, places and notes all work on them exactly as on days recorded by Arc Timeline 4.
On the November plan: deleting the Arc Timeline 3 app won’t free that space by itself, because the databases live in the container Arc Timeline 4 shares, and the button is what clears them. It removes Arc Recorder’s databases too, so the natural order is finish with Arc Timeline 3 (and Arc Recorder, if installed), delete them, then press the button. The old app’s backup files in iCloud Drive (the “Arc App” folder) aren’t part of it, and since 1.7.5 Arc Timeline 4 can import from them (Settings → Backup & Restore → Import Arc Timeline 3 Backups).
Mostly, yep! Though 40% is a greater achievement than I’d expect. But I haven’t checked my own dbs lately to see if mine have achieved similar. Perhaps they have.
The optimisations there are … well the main one will be the more effective and intelligent sample pruning in trips and visits. Arc 3 did a poor job of that, pruning weakly and unintelligently. Arc 3 / LocoKit2 has a much smarter algorithm, and also prunes old data when viewed, while Arc 3 only pruned I think in real time during recording.
That sample pruning can take a visit with 5000 samples down to 500 (or some impressive ratio like that). So that counts for a lot, given samples are the overwhelming bulk of the db.
The other optimisations are more subtle, and probably don’t add up to much. Sample table fields that were text type previously are now number types, when they’re for enums. Like activity type, recording state, etc. In old LocoKit db those strings bloated every row, while in LocoKit2 they collapse down nicely. But yeah, I expect by the numbers that optimisation adds up to much less size savings than the newer smarter sample pruning.