Import vs DirectQuery vs Direct Lake on OneLake vs Direct Lake on SQL
Verdict: Import caches a snapshot and needs a refresh. DirectQuery queries live. Direct Lake loads the latest by default; choose on OneLake for composite models and OneLake Security, on SQL when curated views need DirectQuery fallback.
| Criterion | Import | DirectQuery | Direct Lake on OneLake | Direct Lake on SQL |
|---|---|---|---|---|
| Data freshness | Cached snapshot, explicit refresh required | Queries source live at report time | Loads latest by default, reframing updates pointers | Loads latest by default, reframing updates pointers |
| DirectQuery fallback | Not applicable | Not applicable | None; unsupported table fails | Falls back for views, SQL granular access, or guardrail breach |
| RLS source | Model RLS | Source or model RLS | OneLake Security roles, resolved by effective identity | SQL analytics endpoint security, which forces DirectQuery fallback |
| Composite model | Yes | Yes | Yes: Import in web modelling, DirectQuery via XMLA | No |
| Guardrail breach | Bound by memory | Not applicable | Refresh fails, model cannot be queried | Refresh succeeds with warning, falls back if fallback enabled |
| Connection | Gateway supported | Gateway supported | Cloud only, no gateway | Cloud only, no gateway |
| Choose when | Slow-changing reference data, guaranteed fast visuals | Real-time source of truth, no caching | Lakehouse delta tables; needs composite or OneLake Security | Warehouse SQL endpoint; curated views need graceful fallback |
Rules
- Direct Lake on OneLake enforces row-level security by resolving the effective identity's OneLake Security roles; Direct Lake on SQL relies on the SQL analytics endpoint.
- Direct Lake on SQL falls back to DirectQuery for views, SQL granular access, or a guardrail breach; Direct Lake on OneLake has no fallback.
- Only Direct Lake on OneLake supports composite models (Import tables in web modelling, DirectQuery via XMLA); Direct Lake on SQL does not.
- Direct Lake refresh on either variant works only through cloud connections; no on-premises or VNET gateway is supported.
- Disable the Direct Lake behavior property to make queries fail loudly instead of silently degrading to DirectQuery fallback.
- A composite model is any semantic model holding tables in more than one storage mode.
Traps
- Direct Lake on OneLake does not fall back to DirectQuery; a non-materialised SQL view is simply unsupported there. Only Direct Lake on SQL falls back.
- Import mode caches a snapshot and needs an explicit refresh; it does not translate queries to the source like DirectQuery.
- Defining RLS on the SQL analytics endpoint of a Direct Lake on SQL model does not break refresh; it forces a DirectQuery fallback at report time.
- Dual mode is a table-level hybrid for converting DirectQuery to Import, not the OneLake catalog connection.