Best sync strategy for DTTG to save space on iPad / iPhone

I’m a long time user of DTO pro on my mac and have just bought DTTG for use on my iPad and iPhone. I’ve been looking at the sync info, but wanted to check something before setting up a strategy - because if possible I don’t want to store any of databases on my iPad or iPhone because of space issues.

I’m usually on my home network and can easily manage without access to the databases when traveling. But I do have a few too many databases, and one in particular, an email archive, is massive.

What’s the best strategy to get access to the databases without using up precious storage space on the iOS devices? Thanks in advance for any suggestions.

If you buy the in-app purchase you are able to selectively download files to the local device.

This setting is called “Download Files” either “Always” or “On Demand”.

When this is set at the database level (Tap and hold the database, select “Info” and toggle either “Always” or “On Demand”), this setting sets a default. Any existing file will follow this setting immediately. Subsequently added files will either be downloaded or not based on the database-level setting.

Individual groups have their own setting that can differ from the default database-level setting.

For a given database:
If you want MOST of the groups to be locally downloaded but have only a few you want excluded, set the database to “always” and then change the setting to “on demand” for those few groups. (Note, Groups added on other devices and synced over WILL automatically download to the device)

If you want ONLY A FEW groups to be locally downloaded, then set the database to “on demand” and selectively change those groups you want to “always”. (Note: Groups added on other devices and synced WILL NOT automatically be downloaded to your device)

The other setting to concern yourself with is the “Schedule” setting in the global app settings at the app’s home screen.
Automatic means that the application will only keep the most recently viewed/modified X files, where X is a number like 500 controlled by the slider. This means that files you haven’t touched in a long time in “on demand” databases or groups will automatically be purged. their metadata is still present, but if you want to view the contents they’ll need to be re-downloaded.
Manual means it’s up to you to selectively purge downloaded files you no longer want stored locally (but, of course, can be downloaded at any time again).

NOTE: “Purge” does not remove the file from the database, it simply removes the contents of the file from the locally stored database. The metadata will persist, it will still show up as a member of the group, it will still show up in search results, but if you want to view its contents you have to re-download it. This DOES NOT affect the file on any other devices. Purging it from your iPhone will not, in any way, impact your Mac, or another iOS device, etc.

Hope this helps!

It does help, a lot. Thanks

One thing to remember, text weighs a lot. If you have a database of images with On Demand being used, that will be a more significant conservation of space than a database full of emails or text files. The text is part of the metadata and is added to the index for full-text searching. So if you have a text heavy database, On Demand may take more space that you may expect.

I think the strategies outlined above will be the most straightforward and effective solutions for most folks. However, there are alternative approaches that you may want to consider as options – after all, one of the strenghts of DEVONthink (in my opinion) is its incredible flexibility.

In my case, in the past I’ve had the following setup to conserve space. I put all of my data into a single location on my hard disk (40 gigabytes or so) and index that in my “electronic brain” database. Then, I created a second database just for syncing. I had it only index the folders on my hard disk that I needed to have synced. I only used ad hoc, bluetooth, and wireless syncs.

The benefit of doing this is that you can use indexing to make all of your stuff accessible to other apps, you can keep all of your data off the cloud, and you can easily sync offline (on a plane or out of the country without an internet connection). The drawback (and it is a major one) is that you need to be very, very comfortable and familar with indexing, which can be a little tricky to wrap your head around (simple to set up, but tricky in some ways to use in practice). I recommend a nice Time Machine backup just in case you mess things up (in my case, I’ve messed up a few times, but all through user error, and not due to problems with DEVONthink).

Or, you could purchase an iPad / iPhone with more storage :slight_smile: I’ve found this solved a lot of my issues as well!

There are other interesting strategies you can try. I’ll detail my current setup in a later post. No time to write at the moment. Broadly speaking, it’s similar to what I have discussed on my website.

Thanks Blue and Frob - all good advice

I have a related question. I just changed my sync setup from Dropbox to Bonjour. I have both my databases set to “on demand” downloading of documents, although I maybe have missed that setting on one of them on the phone until too late. My problem is that I have a ton of data on both phone and iPad Pro that I did not intend to have. I don’t normally download a lot of documents. This is an issue primarily on my phone, which is now almost full. And while I love to have a new one with increased capacity, that isn’t in the budget just now.

I set both data bases to keep only 100 documents, which I’m assuming means that at some point the sync or something will purge all but 100. At what point does it do this? Can I force it?

I just looked at the available storage on the phone and it has increased about 1.5 GB since I last look half an hour ago, so maybe it’s working. But I’d like to have some idea about what’s going on.


Using Download Files: On Demand does not necessarily mean it will save a ton of space. If you have a lot of text-heavy documents, the full text is part of the metadata. This allows for full text searching. This can consume a considerable amount of space.

From the manual…

I read that somewhere else but it didn’t sink in until now. Interesting - but I still don’t think it applies. Remember I was syncing the same databases before with Dropbox and didn’t run into space issues.

My free space seems to be increasing, and sync keeps on chugging along, so I think I’m okay, and the excess documents will disappear over time. I know I can purge them, but it’s pretty time consuming for a lot of documents.

Just a thought from a post in a different thread. You can speed up the process by deleting DTG from the phone (thus deleting all data) and reinstalling. I know it’s drastic, and there’s effort involved in setting up the reinstalled app, but if you need that space back really quickly …