Direct Lake vs Import advisor
Answer three questions about a semantic model and get a Direct Lake / Import mode recommendation, based on table maintenance, transform needs, and traffic.
There's no published formula for "which is cheaper" between Direct Lake and Import mode — it genuinely depends on how the source table is maintained, what the model needs to do to the data, and how often the report is opened. This is a decision guide, not a calculator.
Direct Lake
The table can serve this report directly — no refresh to schedule, and it stays current automatically. If the table isn't tuned yet, fix it soon; the benefit compounds as traffic grows.
A decision guide based on the tradeoffs in Direct Lake vs Import mode, not a benchmark. Every report has edge cases the three questions above don't capture — treat this as a starting point.
The three questions, and why they matter
- Is the table V-Order-tuned and compacted? Direct Lake's read speed comes from VertiPaq transcoding Parquet row groups — an un-tuned, small-file table transcodes expensively on every reframe. See V-Order tuning and Delta table optimization.
- Does the report need model-side transforms? Calculated columns and transformations that can't be pushed down have to happen before the model — Direct Lake reads the table as-is.
- How is the report queried? Import's cost is a fixed scheduled refresh regardless of usage. Direct Lake's cost scales with actual reads — a real saving for low-traffic reports, but a risk for high-traffic reports on an un-tuned table, where per-query transcoding can exceed what a nightly refresh would have cost.
Full reasoning and the CU-cost tradeoff: Direct Lake vs Import mode: picking the right one for your semantic model.
This tool doesn't know your actual query volume or table state — it's a starting point for the conversation, not a substitute for checking V-Order and compaction status on the real table.
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