02 Review and approve the design — instructor notes

Timing

Budget 40 minutes: 10 for the summary, 20 for paired review, and 10 for one challenge and DDL approval. Announce the role swap after approval.

Talk track

Use the supplied discovery-summary screenshot to orient the room, then make pairs inspect their own result. Require workload-driven ORDER BY, exact Decimal, explicit timestamp zones, intentional JSON/nested representations, generated-column behavior, and an honest disposition for deletion vectors/time travel.

The reviewer challenges one consequential choice in chat and asks for live source and workload evidence. At the final DDL prompt, learners say yes only after the revision appears. Step 1 is complete when clickhousectl creates the target and SHOW TABLES succeeds—not when DDL merely appears in chat.

Common failures

• Learners copy source CLUSTER BY directly into target ORDER BY.
• VARIANT becomes opaque String, money becomes Float64, or timezone semantics collapse.
• The agent asks for approval before exposing the complete DDL.
• A learner says yes to save time and plans to repair the schema after loading.
• A challenge asks for opinion but not source observation or workload evidence.

Reset steps

Ask the agent to restate the disputed observation, query pattern, and revised DDL. If tables were created prematurely, stop before Step 2, remove only those empty workshop tables through the agent, and repeat the approval gate. Preserve the conversation rather than recreating a clean success story.