Looking at King Crimson (as an example), and Ian McDonald, an original member, in the l_artist_artist table, there are five separate links. Each of these links has two attribute tags, one being “original” and the other being one of 5 different instruments.
My question is, why isn’t it a single link with 6 attribute tags? Is this a case of duplicate input, or is there an actual reason for it?
The id for King Crimson is 2259, the id for Ian McDonald is 350106, and the links in question are 111010, 742692, 742693, 742694, and 742695. The last four were clearly added at the same time, since they’re consecutive ids.
And the beginning and end dates for the link are identical for all 5 links.
A while ago it was decided to split each instrument into its own relationship (but merge them for display in the UI). This was done to make data entry and storage more consistent; previously an editor could* set any number of instruments on a relationship, which meant that all of the following were allowed to exist simultaneously:
original member: Ian McDonald (background vocals)
original member: Ian McDonald (background vocals, flute)
original member: Ian McDonald (flute)
original member: Ian McDonald (flute, saxophone, mellotron, keyboard)
Note how each relationship could have a different number of instruments, and could overlap/duplicate instruments on other relationships (so long as the sets weren’t identical). Splitting them was a way to standardize how they were stored and prevent such duplication.