I’ve copied most of your content below and put suggested changes/additions in bold text. Hope this helps and happy to discuss any of it further. If you don’t mind, we might even borrow some of it to build out more “official” documentation. 
Dataset 1: changesByDate
This can be generalized to:
| Column Name | Data Type | Description |
|---|---|---|
| Date | Date | The date of the entry, indicating when the changes were logged. |
| {STATUS} | Integer | The number of supercharge stations that were updated with the given status on the given date. {STATUS} can be any of the following: CLOSED_PERM, CLOSED_TEMP, VOTING, PLAN, PERMIT, CONSTRUCTION, EXPANDING, OPEN. |
Dataset 2: allSites
Each site:
| Column Name | Data Type | Description |
|---|---|---|
| id | Integer | Unique identifier for each supercharging station entry. |
| locationId | String | A unique location identifier for the supercharging station, typically a descriptive string. |
| name | String | Name or description of the supercharging station, often including the city and state or region. |
| status | String | Current operational status of the station (e.g., OPEN, CLOSED). |
| address | Object | Nested structure containing detailed address information. |
| - street | String | Street address of the supercharging station. |
| - city | String | City where the supercharging station is located. |
| - state | String | State or province where the supercharging station is located. |
| - zip | String | Postal code for the supercharging station location. |
| - countryId | Integer | Numeric identifier for the country where the station is located. |
| - country | String | Country where the supercharging station is located. |
| - regionId | Integer | Numeric identifier for the region where the station is located. |
| - region | String | Region where the supercharging station is located (e.g., North America, Europe). |
| gps | Object | Nested structure containing GPS coordinates. |
| - latitude | Float | Latitude of the supercharging station. |
| - longitude | Float | Longitude of the supercharging station. |
| dateOpened | Date | Date (if any) when the supercharging station was opened. |
| hours | String | For sites that are not open 24/7, text indicating hours of availability for charging. (Note this is separate from the “facilityHours” field.) If this field is missing/null/blank, the site is available for charging 24/7. |
| stallCount | Integer | Number of charging stalls available at the station. |
| counted | Boolean | Indicates whether the station’s stall count is included in Tesla’s official network count. |
| elevationMeters | Integer | Elevation of the station in meters above sea level. |
| powerKilowatt | Integer | Maximum power output of the chargers at the station, in kilowatts. |
| solarCanopy | Boolean | Indicates whether the station is equipped with a solar canopy. |
| battery | Boolean | Indicates if there is battery storage available at the station. |
| otherEVs | Boolean | Indicates if chargers are compatible with electric vehicles other than Tesla. (Note: use this in conjunction with the “plugs” field to determine whether an adapter is required.) |
| statusDays | Integer | For sites that are not OPEN, number of days since the site changed to its current status. (For OPEN sites, use the “dateOpened” field instead.) |
| urlDiscuss | Boolean | Indicates if a URL or forum link for discussion about the station is available. |
| stalls | Object | Detailed information about types of charging stalls available at the station. |
| - urban | Integer | Number of urban Tesla supercharger stalls. |
| - v2 | Integer | Number of version 2 Tesla supercharger stalls. |
| - v3 | Integer | Number of version 3 Tesla supercharger stalls. |
| - v4 | Integer | Number of version 4 Tesla supercharger stalls. |
| - other | Integer | Number of stalls of unknown or other type/version. |
| - accessible | Integer | Number of accessible stalls designated for disabled access. |
| - trailerFriendly | Integer | Number of stalls accessible for vehicles with trailers. |
| plugs | Object | Details about the types and numbers of charging plugs available at the station. |
| - tpc | Integer | Number of Tesla proprietary connector plugs. |
| - nacs | Integer | Number of North American Charging Standard plugs. |
| - ccs1 | Integer | Number of Combined Charging System version 1 plugs. |
| - ccs2 | Integer | Number of Combined Charging System version 2 plugs. |
| - gbt | Integer | Number of Chinese GB/T standard plugs. |
| - multi | Integer | Number of stalls that support more than one type of connector (e.g. via multiple cables or MagicDock). |
| - other | Integer | Number of plugs of unknown or other type/version. |
| - type2 | Integer | Number of Type 2 connector plugs (AKA Mennekes, common in Europe). |
| parkingId | Integer | An identifier for the parking rules and fees where the charging station is located. (See Dataset 4 below.) |
| facilityName | String | Name of the host or primary facility where the charging station is housed (e.g., shopping center, parking lot). |
| facilityHours | String | Operating hours of the host or primary facility where the charging station is located. (Note: This is separate from the “hours” field. If this field is blank or missing, the facility’s hours are simply unknown / not recorded.) |
| plugshareId | Integer | Identifier for the station on PlugShare, a popular EV charging station locator and review platform. |
| osmId | Integer | Node Identifier for the station on OpenStreetMap, providing mapping details. |
| accessNotes | String | Additional notes about accessing the charging station, such as site-specific parking rules/fees/hours, required adapters or restrictions. |
| addressNotes | String | Additional notes about locating the charging station, such as which entrance to use, what level of the garage, etc. |
Dataset 3: allChanges
| Column Name | Data Type | Description |
|---|---|---|
| id | Integer | Unique identifier for the change record. |
| siteId | Integer | Identifier linking to a specific supercharging site. |
| date | Date | The date when the change was recorded. |
| changeType | String | Type of change made (e.g., ‘ADD’, ‘UPDATE’). |
| siteStatus | String | Current status of the site after the change (e.g., ‘OPEN’, ‘CONSTRUCTION’). |
| prevStatus | String | Previous status of the site before the change, if any. |
| stallCount | Integer | Number of charging stalls after the change. |
| prevCount | Integer | Number of charging stalls before the change, if known. |
| powerKilowatt | Integer | Power capacity of the site in kilowatts. |
| notify | Boolean | Indicates whether notifications for the change were sent out. |
| siteName | String | Descriptive name of the supercharging site. |
| regionId | Integer | Numeric identifier for the region where the site is located. |
| region | String | Name of the region where the site is located (e.g., ‘Asia Pacific’, ‘Europe’). |
| countryId | Integer | Numeric identifier for the country where the site is located. |
| country | String | Country where the site is located. |
| state | String | State or province where the site is located. |
| site | Object | Detailed information about the site including its complete address, GPS coordinates, and more. Same fields as Dataset 2. Note that some of the top-level fields in the “allChanges” dataset (e.g. powerKilowatt, region, country, state) are redundant copies of what’s in the “site” object and might be removed or changed in a future release. |
| dateFormatted | String | Formatted date string representing the date of the change. |
Dataset 4: parking
There are currently only 7 rows in this lookup table; it is meant to indicate a general policy (e.g. free always vs sometimes, self vs valet, etc). It is NOT meant to be a detailed, site-specific value.
| Column Name | Data Type | Description |
|---|---|---|
| parkingId | Integer | Unique identifier. |
| name | String | Short name of parking rules and fees (e.g. “Free at all times” or “Paid - self parking”). |
| description | String | Detailed description of parking rules and fees. |
Joins Summary
Not sure specifically what you were looking for here. For joining among supercharge.info datasets, I generally recommend using siteId, regionId, or countryId. Use locationId only for joining with Tesla’s own data.