In macOS Mojave, Apple changed the way that Spotlight indexes the contents of plain text files. That introduced a bug that prevents indexing of any of the contents of files starting with certain characters. For many Macs, that bug won’t ever be fixed.
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From Ventura (if not earlier) to Tahoe, Spotlight appears unable to index text files that start with two specific letters. Although those are exceedingly rare, this could still catch you out.
Looks at how Spotlight adds a batch of new files to its volume indexes, and how it handles and answers queries.
Apple’s several patents cast new light on how Spotlight indexes the metadata and contents of local files, and why mds and other processes need to reindex periodically.
Finder tags should sync in iCloud Drive, and should be found when you use Spotlight search for their tag labels. Here’s what to check when there are problems.
How Spotlight works, Core and global Spotlight, importing failure, exclusions from indexing, re-indexing, excessive re-indexing, failure to find, iCloud Drive and network shares.
Try searching for something you know is in a file in ~/Library/Preference and you’re unlikely to get any success. This explains how, and why you can’t alter that.
Why Spotlight can now take a long time building and updating its volume indexes. Understand when forcing them to be rebuilt is a good idea, and when it isn’t.
Are you worried about your Mac maxing out its E cores after starting up in Sequoia? There may be nothing wrong about this, as explained here.
When you start your Mac up, the fans blow full on, and you see CGPDFServices taking lots of CPU %. Is this malware? No, but it’s new in Sonoma.
The Eclectic Light Company 