Ideal number of databases to keep

Dear friends,
I am using DEVONthink Pro office for all my personal and professional file management and note taking needs. Up until now I have been keeping a number of databases - e.g. reviews, manuscripts, publications, presentations, curriculum vitae and biosketches, conferences and workshops, notes, etc - However, this has proven not as practical in that at times I run into instances when it is not clear where it would be best to safe a document. I am thinking of restructuring my documents into two databases: professional and personal. Is there a disadvantage to doing that? I can only think of problems arising if the size of the professional database, for example, ends up being too large. How large can a database be?
I thank you in advance for your advice.
Best wishes

Christian has noted that the maximum size of a database is about 200,000 documents and about 300,000,000 total words.

But I wouldn’t find the performance of a database of that size acceptable to run on my 2011 MacBook Air with 2-core i7 CPU and 4 GB RAM. I work with topical databases each of which meets a particular need or interest, and try to keep them at 40,000,000 total words or less. As a practical matter, that size applies to the total word count if multiple databases are open. I treat my modular databases as informational Lego blocks. (Let’s face it, 40,000,000 total words is in fact a great deal of information.)

As long as I keep a ‘headroom’ of about 1,000 MB free physical RAM, everything flies. Searches are fast and See Also suggestions (which I use a great deal) pop up almost instantly. As Apple’s memory management is good but not perfect, over time the amount of inactive data occupying RAM may accumulate. When free RAM drops below about 1,000 MB I use a utility to release inactive data and so increase available free RAM. That’s done to avoid moving over into heavy use of Virtual Memory swap files, and consequent slowdowns resulting from moving data back and forth between RAM and disk. (The 256 GB SSD in the MB Air somewhat mitigates slowdown resulting from heavy use of swap files, but I hate to pound it too much.)

Bottom line, your decision on whether or when to start splitting up a database as it grows may depend on your tolerance for speed. I don’t tolerate seeing a spinning ball. But I know of one user who is comfortable with slow performance, as everything is in one very large database and gives him results.

Thanks for your helpful comments!