LookML to ktx Semantic Layer

LookML views map to SL sources, measure: to measures, explore: { join: } to the join graph. This skill lays out the mapping and the three capture shapes.

Mapping table

LookML	ktx form	Notes
view: X { sql_table_name: …; measure:/dimension:/join: }	Overlay named X with measures, computed-only columns, column_overrides, joins, segments	Manifest-backed; inherit grain/columns
view: X { derived_table: { sql: … } }	Standalone with top-level sql:, explicit grain: + columns:	No manifest entry exists
view: X { sql_always_where: <p> }	Standalone with sql: SELECT * FROM <base> WHERE <p>	Enforcement, not opt-in
explore: { join: Y { sql_on: …; relationship: … } }	joins: entry { to: Y, on: "<local> = Y.<col>", relationship: … }	On the overlay or standalone
conditionally_filter / always_filter	segments: [{ name, expr }]	Callers reference by name
Manifest entry	_schema/*.yaml	Never edit - auto-imported

Type map: date/datetime/timestamp → time; yesno → boolean; number → number; string → string. Ignore drill_fields: (UI only).

Decision rules

LookML writes target the run connection directly. Unlike Looker runtime ingestion, the LookML adapter is configured on the warehouse ktx connection, so do not look for targetWarehouseConnectionId and do not route through a mapping array.

Before any SL write, inspect the WorkUnit notes.

If notes contain:

[LOOKML SL WRITES DISALLOWED]
reason: lookml_connection_mismatch
...
[/LOOKML SL WRITES DISALLOWED]