Model Builder

The Model Builder is a builder Mind that turns an approved design into a semantic model. It works in rounds inside your chat with the Warehouse Builder, reports each round back as a card, and calls on you when it needs a decision. To read each card it shows, see Model Builder cards.

Start a build

1. Open a chat with the Warehouse Builder Mind and run /star-schema.
2. Review the design it proposes and approve it, or reject it with a note. The model is created from the approved design. See The semantic model design card.
3. The build then works through the design in rounds, on its own between your decisions.

For the whole flow around the chat, from the request to the working model, see Design and hand over a semantic model.

While it builds

• A strip above the message box keeps the session in view: Model Builder · {model} · {round text} · {state}, with a Needs you badge when something waits. Select the strip to open the session card; on a phone it opens as a bottom sheet.
• Its state starts at Getting ready, becomes Working or Model AI building, round {n} of {m}, pauses as Waiting for the Model AI chat or Needs you, and ends as Done, Stopped or Failed.
• Rounds run in the model's Model AI chat, one after another. The brief for each round is posted there, and each round files a report back into your chat as a card.
• SQL never crosses between the chats: briefs describe the work in words, not query text.
• A round that cannot start because the Model AI chat is busy parks, and starts by itself when the chat is free.

Answer questions and decide

• A question from the build appears in the session card's Needs you section. Pick one of the choices, or write your own answer in the field; Send answer sends it, and Enter works too. An answer can hold up to 2000 characters.
• If the build wants to change a table that existed before the design, it asks first, under The Model Builder needs a change on a shared table. Choose I will make it in the Warehouse Builder chat to do it yourself, or Continue without it to let the build carry on and skip that change. The hint reads "This table existed before this design, so the Model Builder changes it only with your word."
• A decision on a change the Model AI wants appears as an approval row: Approve, or Reject with an optional note. The change itself is applied or dropped in the Model AI chat.
• If a personal-data check warns about one of your answers, you can send it on with Send anyway.

Stop, continue or start again

The session card's footer holds the actions.

• Stop ends the build for now. Confirm with Stop in the dialog; it reads "The Model Builder stops working on this model. Anything it made stays; you can start it again."
• Continue with 2 more rounds appears when the session stopped at its round limit. It adds two rounds, once per session, and only the person who started the build can use it. Everyone else sees Only {name} can give it 2 more rounds.
• Start again begins a fresh session for the same design. It is for the person who started the build, and it is available once the current session has ended.
• Open model opens the semantic model in DataPrism; Open Model AI chat opens its Model AI panel. See Semantic models and BI tables and Model AI.

A notice confirms each action: Model Builder stopped, Model Builder sessions reset or Answer recorded. A failed action reads Stop failed, Continue failed or Start again failed.

When a session ends

• The done card reports the outcome, with a scorecard and its open items. Open items list what still wants attention, in this order: slow charts, questions, change requests, the full history, failed tests, model checks. For reading it, see Model Builder cards.
• When the build ends on its own, a close notice says why in plain words. The endings you may see:
  • All rounds used: "Used all 8 rounds. Continue with 2 more rounds, or open the Model AI chat to finish by hand."
  • Time limit reached: "Reached its 12-hour limit. Start a new session from this chat, or finish in the Model AI chat."
  • Token budget used: "Used its 30M token budget. Start a new session from this chat."
  • A repeated request: "The Model AI asked for the same thing three times. Decide here, then start a new session."
  • Rounds not finishing: "Two rounds in a row did not finish. Start a new session."
  • Access or model gone: "The requester can no longer use this model's Model AI." or "The model was deleted."
  • Model not complete: "Finished without a complete model: see the open items."
  • Start or run failure: "The Model Builder could not start." or "The Model Builder failed while it worked."

The full history load

A design can ask for the full history of its fact tables.

• The load runs once per design; a second full load needs a new design card.
• Backfills run one at a time, with eco query settings, so they are gentle on the warehouse.
• The card notes when every load has finished and the Model Builder is woken. It then checks each table's health and continues; findings come back as open items.

Limits

One build works on a model at a time. While a session is open, another one is refused with "A Model Builder is still working on this model."

Who can see and act

• You read a session with the same access that lets you view the chat.
• Taking part, including stopping the build, answering its questions and deciding its approvals, needs the permission to write in the chat. A question that only writers can answer says Someone who can write in this chat answers this question.
• Continue with 2 more rounds and Start again belong to the person who started the build.
• Where a viewer cannot use the model's Model AI, its text appears as a stub: "Only people who can use this model's Model AI can read it."
• While you view DataMind OS as another user, you can read a session but not act on it. See Impersonate a user.

Questions, answered

How is the Model Builder different from Model AI?

Model AI is the assistant panel where you ask for changes on a semantic model. The Model Builder is a build that runs by itself: it works from an approved design, in rounds, and reports back into your Warehouse Builder chat. You follow and steer it from the session card without opening the model. See Model AI.

How many rounds does the Model Builder get?

Eight rounds per session. When it uses them all, the person who started the build can add two more with Continue with 2 more rounds, once per session. A session also ends at its 12-hour limit or when it uses its 30 million token budget.

Who can give the Model Builder 2 more rounds?

The person who started the build. Everyone else sees Only {name} can give it 2 more rounds. on the card. Start again is theirs as well.

What is the difference between Continue and Start again?

Continue with 2 more rounds adds two rounds to the same session, when it stopped at its round limit, and works once per session. Start again begins a fresh session for the same design, and is for the person who started the build once the current session has ended.

What happens to the model if I stop the build?

Nothing is rolled back. The Model Builder stops working on this model and anything it made stays, and you can start it again.

The build asked me about a table that existed before the design. What do the two options mean?

I will make it in the Warehouse Builder chat keeps the change in your hands: the build skips it and you do it yourself. Continue without it lets the build carry on without that change. The build changes only the tables the design created or changed, so it asks before touching anything older.

Does the full history load by itself?

It runs once per design, one table at a time, and the card shows its progress. When every load has finished, the Model Builder is woken, checks each table's health and continues. A second full load needs a new design card.

Why can't I read a round's report?

Parts of a round's output come from the model's Model AI chat. If you cannot use that model's Model AI, they appear as stubs: "Only people who can use this model's Model AI can read it." You can still follow the session's states and decisions.

Can I answer the build's questions if I did not start it?

Yes, if you can write in the chat. Questions are answered in Needs you by anyone who can write there; the hint reads Someone who can write in this chat answers this question. The extra rounds and Start again stay with the person who started the build.

What is the strip above the message box?

It is the Model Builder session strip. It reads Model Builder · {model} · {round text} · {state}, with a Needs you badge when something waits. Select it to open the session card.

Can I leave the chat while the build runs?

Yes. The build runs on its own between your decisions and keeps reporting into the chat; come back when the card, the strip or a notice calls on you.