Compare schema snapshots

Compare the current schema with a saved snapshot, grouped by cause, and tick off what you planned.

Compare shows what changed between the current schema and a saved snapshot. Use it to check that a change did what you planned and nothing else, or to see how two environments differ.

Causes and side effects

One edit can change many types. Add a property to a composition, and every type that composes it changes too. Compare groups the changes so you can tell the edit from what it caused.

A cause is a type with edits of its own:

• the type was added or removed
• properties were added, removed or changed, or a property got a new Data Type
• its groups or tabs changed
• its compositions, allowed children, or block or picker targets changed

A side effect is a type that only changed because of a cause, and sits under it:

• every type that composes or inherits a composition whose properties changed
• every Element Type whose incoming block relationship changed because a host’s block list did
• every type whose incoming picker or allowed-child relationship changed, and every parent that gained or lost an allowed child because that child type was added or removed

A type with an edit of its own stays a cause even when it is also a side effect, and says what else it is a side effect of. Every change sits under the causes that explain it, so nothing is dropped. The summary reads, for example, “4 causes, 48 side effects, 1 unplanned”.

Mark what you planned

Tick each cause you planned with its Planned box, use Mark all as planned, or Paste a plan as a list of type aliases. Show unplanned only then leaves the changes nobody asked for. The plan lasts as long as the baseline does.

• Copy as Markdown gives a ticket-ready list, with both snapshots’ hosts and dates, the totals, each cause ticked when planned, and its side effects nested under it.
• Export CSV gives one row per line, with the cause it belongs to, whether it is the cause’s own edit or a side effect, and whether it was planned.

See the changes in the city

While a baseline is loaded, the city shows a change layer and dims everything else:

• added types are azure
• types changed by their own edit are amber with a ring
• side effects are a quieter amber
• removed types are outlines where they stood

Choosing a lens replaces the change layer until the lens is off again. Show in city, from the Impact page or a Data Type, replaces it until you clear it. The List view gets a Change column, sortable and filterable, with a row for each removed type.

Matched buildings keep their baseline positions. New types appear on separate added boards.