Understanding tags...

[rafikiphoto 23]

When a tag is attached to a note where is that information stored? Is it with each note or is there a database holding the links?

[gazumped 11,897]

AFAIK it's part of the main database,  stored as metadata in each record for the note(s) to which it is attached.  There's no identifiable separate tags file.

[blakesphere 13]

If I was designing a system with tags, it would be a many-to-many relationship in the database structure. So tags in a tags table joined (directly or indirectly) to the notes table.

[DTLow 5,741]

42 minutes ago, blakesphere said:

If I was designing a system with tags, it would be a many-to-many relationship in the database structure. So tags in a tags table joined (directly or indirectly) to the notes table.

I used the Evernote Legacy product on a Mac which stored a local copy of the database
The metadata was stored in a small sql database, with the table structure you described       
(a notes table, a tags table, a note/tag table)    
The tags table contained tag-id, tag-name, tag-parent   
The note/tag table contained note-id and tag-id
The note contents were stored separately from the database; a separate folder for each note holding a .enml file