Why use multiple databases?

Related to another topic here, inquiring what databases we use, I’m wondering why use multiple databases at all. I can think of several reasons:

  • As “super-folders,” segregating high-level topics from each other. A person might have one database for the day job, another for a side-business, others for each of their hobbies (gardening, photography, playing jazz music, whatever), others for personal finance, an inbox, etc. This value is largely psychological.
  • As firebreaks against corruption. If one database gets corrupted, other would be spared.
  • To archive old projects that are no longer active, but for which the user wants to retain information.
  • To control what gets synced between multiple Macs, iPhones, and iPads.
  • To experiment with indexing, syncing, smart rules, etc., without risking corrupting working databases. E.g. “Hold my beer while I do this”
  • ?

Are you a one-big-database person? Do you have a few databases? Or do you have MANY databases?

I think I’ve read somewhere that it might be useful to segregate your databases by language-- so to avoid “false friends” when searching though them.

I have a personal database that stores stuff that’s at best tangentially related to my research interests.

I think I’ve read somewhere that it might be useful to segregate your databases by language-- so to avoid “false friends” when searching though them.

I’m an American. I am barely literate in English.


I have just split a large database into several (7) smaller databases. I decided to give it a try because I was unhappy seeing legitimate but contextually unhelpful results showing up in my searches, and because having a recipe for scones in the same database as notes about minecraft seems illogical to me.

I had hoped that having unrelated information in the same database would reveal interesting links, but it has proved to be a distraction and hasn’t provided anything helpful. Ultimately though, I think I work better with distinct units of information.


I use a single database; 12GB, 15,000+ notes


I also basically use a single folder
For organization, I use Tag methodology
For archiving, I use an archive or completed tag


I have been using a single database for the last 2-3 years, I am cleaning up DT after being inspired by MacSparky’s Field Guide. I am experimenting for the next few months with multiple databases. The nice thing that I am finding out so far is that practically speaking I don’t need “everything” with me at all times when I am out and about.


I’ve been using DT for about 4 years and only recently split up from a single large database — prompted by MacSparky’s Field Guide, and reading through this Forum.

I’ve now got about 20 project-related databases and a Records database for housekeeping files.

With this new structure, I find that I’m paying more attention to tags, since they are now relevant to a single project. I’m getting much more introspection.

Also, I can selectively choose what to carry with me on my phone or tablet.

However, I’m still exploring the Preferences options to Merge Tags and seeing if that helps or hinders.


I use multiple databases to achieve a few things:

  • To enable simple selective synching, e.g. I don’t want everything synced to iPhone! (Only “works in progress” in WIP database, and one to read stuff)

  • To segregate personal, financial, business, major topics

It’s not a momentous or even an important issue to debate, frankly, since it’s so simple to drag stuff from one database to another if one changes their mind on how stuff should be organised.


I agree. I will fairly regularly switch the way I work with my information, or the way I collect information. Often as a result of having arrived at an overcompliced structure, which is to say, having muddied any structure I might have once had. DTP’s flexibility makes this pretty much pain free.


One conclusion I have come to after separating my database into multiple project-related databases is that I now have to accept that wikilinks are much less useful.

Wikilinks and “Reveal Tags” only seem to work within a DEVONthink database; so if you are trying to find all interactions with a contact, for example, you can no longer do that with records separated into separate databases.

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Another reason to add to the list: you may want to encrypt a database of important information, but not need to encrypt other databases.

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