[DNSB]

Forgot to mention that the book count seems to include all libraries. Running Power Search in a library with 43 books, one search found 4 books with the search term but reported 1475 books found. A second search with a different search term found 5 books but reported 1271. A third search with yet another search term found 3 books and reported 991.

When I switched to the main library, I got book counts that came close to matching the number shown as found.

Hmmmm... a search on 'the' found 10000 books.

And for a bug report. When I switch libraries with Power Search and try to do a search, I get a NoneType object has no attribute error. See spoiler.

Spoiler:

calibre, version 5.4.2
ERROR: Unhandled exception: <b>AttributeError</b>:'NoneType' object has no attribute 'library_id'
calibre 5.4.2 [64bit]  embedded-python: True is64bit: True
Windows-10-10.0.19041 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19041')
Python 3.8.5
Windows: ('10', '10.0.19041', '', 'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: DeDRM (7, 0, 0) && Annotations (1, 13, 0) && Baen (1, 2, 0) && Barnes & Noble (1, 2, 16) && Calibre Power Search Plugin (1, 7, 0) && Count Pages (1, 11, 0) && Diaps Editing Toolbag (0, 3, 7) && EpubCheck (0, 2, 3) && EpubMerge (2, 11, 0) && EpubSplit (3, 0, 0) && FanFicFare (3, 24, 0) && Fantastic Fiction (1, 4, 0) && Find Duplicates (1, 8, 3) && Goodreads (1, 5, 1) && Hyphenate This! (0, 1, 3) && Job Spy (1, 0, 188) && Kindle hi-res covers (0, 5, 0) && KindleUnpack - The Plugin (0, 82, 3) && Kobo Books (1, 8, 0) && Kobo Utilities (2, 11, 9) && KoboTouchExtended (3, 4, 1) && Modify ePub (1, 6, 1) && Obok DeDRM (6, 7, 0) && Open With (1, 5, 13) && Quality Check (1, 10, 1) && Resize Cover (1, 1, 0) && ScrambleEbook (0, 4, 5) && SmartEject (2, 3, 0) && Smashwords Metadata (1, 0, 2)
Traceback (most recent call last):
  File "calibre_plugins.caps.main", line 235, in on_search
  File "calibre_plugins.caps.main", line 276, in _reindex
  File "calibre\db\cache.py", line 171, in library_id
AttributeError: 'NoneType' object has no attribute 'library_id'