The question reads like an XY problem, they describe DB functions for data structures so unless there’s some specific reason they can’t use a DB that’s the right answer. A “spreadsheet for data structures” describes a relational database.
But they need rectangular structure. How do they work on tree structures, like OP has asked?
Relationships. You don’t dump all your data in a single table. Take for instance the following sample JSON:
JSON
"users": [
{
"id": 1,
"name": "Alice",
"email": "alice@example.com",
"favorites": {
"games": [
{
"title": "The Witcher 3",
"platforms": [
{
"name": "PC",
"release_year": 2015,
"rating": 9.8
},
{
"name": "PS4",
"release_year": 2015,
"rating": 9.5
}
],
"genres": ["RPG", "Action"]
},
{
"title": "Minecraft",
"platforms": [
{
"name": "PC",
"release_year": 2011,
"rating": 9.2
},
{
"name": "Xbox One",
"release_year": 2014,
"rating": 9.0
}
],
"genres": ["Sandbox", "Survival"]
}
]
}
},
{
"id": 2,
"name": "Bob",
"email": "bob@example.com",
"favorites": {
"games": [
{
"title": "Fortnite",
"platforms": [
{
"name": "PC",
"release_year": 2017,
"rating": 8.6
},
{
"name": "PS5",
"release_year": 2020,
"rating": 8.5
}
],
"genres": ["Battle Royale", "Action"]
},
{
"title": "Rocket League",
"platforms": [
{
"name": "PC",
"release_year": 2015,
"rating": 8.8
},
{
"name": "Switch",
"release_year": 2017,
"rating": 8.9
}
],
"genres": ["Sports", "Action"]
}
]
}
}
]
}
You’d structure that in SQL tables something like this:
Tables
dbo.users
| user_id | name | |
|---|---|---|
| 1 | Alice | alice@example.com |
| 2 | Bob | bob@example.com |
dbo.games
| game_id | title | genre |
|---|---|---|
| 1 | The Witcher 3 | RPG |
| 2 | Minecraft | Sandbox |
| 3 | Fortnite | Battle Royale |
| 4 | Rocket League | Sports |
dbo.favorites
| user_id | game_id |
|---|---|
| 1 | 1 |
| 1 | 2 |
| 2 | 3 |
| 2 | 4 |
dbo.platforms
| platform_id | game_id | name | release_year | rating |
|---|---|---|---|---|
| 1 | 1 | PC | 2015 | 9.8 |
| 2 | 1 | PS4 | 2015 | 9.5 |
| 3 | 2 | PC | 2011 | 9.2 |
| 4 | 2 | Xbox One | 2014 | 9.0 |
| 5 | 3 | PC | 2017 | 8.6 |
| 6 | 3 | PS5 | 2020 | 8.5 |
| 7 | 4 | PC | 2015 | 8.8 |
| 8 | 4 | Switch | 2017 | 8.9 |
The dbo.favorites table handles the many-to-many relationship between users and games; users can have as many favourite games as they want, and multiple users can have the same favourite game. The dbo.platforms handles one-to-many relationships; each record in this table represents a single release, but each game can have multiple releases on different platforms.
Sort of, but but really. You’re right that historically the daylight hours set an upper limit on the amount of work that can be done per week for most types of work, but that limit is far higher than 8 hours per day over 5 days. The 40 hour work week is based on unions fighting for a 40 hour work week. If it wasn’t for the unions you’d be working all day every day except Sunday, for religious reasons.
That might change over the next few decades too, the current fight is for a 4 day work week and studies are showing promising results there.