Question: I have some very large PDFs (some 1000 pages or more). For performance and speed, would I be better keeping these as external files to a database? I often use Acrobat Pro to annotate or modify these files.
Whether you Import or Index a large PDF makes no real difference in performance of the database.
The text content of the PDF is indexed and adds to the memory requirements of the open database. But the PDF isn’t opened within the database (which also adds to memory requirements) until it is selected in the database, e.g., in the Three Panes view. In that Three Panes display of a selected PDF, you won’t see a detectable difference in the time required to open the PDF based on its storage location, assuming that the read speeds of the storage locations inside or outside the database are the same.
Users can have a variety of reasons for choosing between Import and Index capture of some or all items to a database. For example, files that are to be shared with another application should probably be Indexed rather than Imported. In my own case, I generally prefer Import captures, as that gives me more freedom to organize and reorganize the content without creating problems, and I can make full use of the Classify or Auto Classify assistants in DEVONthink.