@prefix rdf: . @prefix rdfs: . @prefix owl: . @prefix xsd: . @prefix dcterms: . @prefix vann: . @prefix obsl: . # ============================================================================= # OBSL --- OrionBelt Semantic Layer Core Vocabulary 0.1 # # A vocabulary for describing business-level semantic-layer concepts: # semantic models, data objects, columns, joins, dimensions, measures, # and metrics. Complements OBA (OrionBelt Analytics Ontology) which # describes physical database schema metadata. # # Published at: https://ralforion.com/ns/obsl/ # Namespace: https://ralforion.com/ns/obsl# # ============================================================================= obsl: a owl:Ontology ; owl:versionIRI ; owl:versionInfo "0.1" ; rdfs:label "OrionBelt Semantic Layer Core Vocabulary" ; rdfs:comment "Business-level vocabulary for semantic models, dimensions, measures, and metrics. Designed for OBML-based model authoring and graph-based semantic-layer tooling." ; dcterms:creator "Ralf Becher" ; dcterms:created "2026-04-01"^^xsd:date ; dcterms:license ; vann:preferredNamespacePrefix "obsl" ; vann:preferredNamespaceUri "https://ralforion.com/ns/obsl#" . # ============================================================================= # 1. CLASSES # ============================================================================= obsl:SemanticModel a owl:Class ; rdfs:label "Semantic Model" ; rdfs:comment "Top-level container representing a complete semantic-layer model. Groups data objects, dimensions, measures, and metrics." . obsl:DataObject a owl:Class ; rdfs:label "Data Object" ; rdfs:comment "A physical data source (table or view) referenced by the semantic model. Identified by database, schema, and code." . obsl:Column a owl:Class ; rdfs:label "Column" ; rdfs:comment "A column within a data object. Carries a physical code and an abstract result type." . obsl:Join a owl:Class ; rdfs:label "Join" ; rdfs:comment "A join path between two data objects, defined by source/target columns and cardinality." . obsl:Dimension a owl:Class ; rdfs:label "Dimension" ; rdfs:comment "A grouping or filtering attribute exposed to analysts. References a column in a data object." . obsl:Measure a owl:Class ; rdfs:label "Measure" ; rdfs:comment "An aggregated numeric value derived from a source column or expression." . obsl:Metric a owl:Class ; rdfs:label "Metric" ; rdfs:comment "A derived, cumulative, or period-over-period calculation built on top of one or more measures." . obsl:CumulativeMetric a owl:Class ; rdfs:subClassOf obsl:Metric ; rdfs:label "Cumulative Metric" ; rdfs:comment "A metric that applies a time-windowed aggregation over a base measure. Supports running totals, rolling windows, and grain-to-date resets." . obsl:PeriodOverPeriodMetric a owl:Class ; rdfs:subClassOf obsl:Metric ; rdfs:label "Period-over-Period Metric" ; rdfs:comment "A metric that compares a measure's value across consecutive time periods using a date spine. Supports ratio, difference, previous value, and percent change." . # ============================================================================= # 2. OBJECT PROPERTIES --- Model composition # ============================================================================= obsl:hasDataObject a owl:ObjectProperty ; rdfs:label "has data object" ; rdfs:comment "Links a semantic model to one of its data objects." ; rdfs:domain obsl:SemanticModel ; rdfs:range obsl:DataObject . obsl:hasDimension a owl:ObjectProperty ; rdfs:label "has dimension" ; rdfs:comment "Links a semantic model to one of its dimensions." ; rdfs:domain obsl:SemanticModel ; rdfs:range obsl:Dimension . obsl:hasMeasure a owl:ObjectProperty ; rdfs:label "has measure" ; rdfs:comment "Links a semantic model to one of its measures." ; rdfs:domain obsl:SemanticModel ; rdfs:range obsl:Measure . obsl:hasMetric a owl:ObjectProperty ; rdfs:label "has metric" ; rdfs:comment "Links a semantic model to one of its metrics." ; rdfs:domain obsl:SemanticModel ; rdfs:range obsl:Metric . obsl:belongsToModel a owl:ObjectProperty ; rdfs:label "belongs to model" ; rdfs:comment "Inverse convenience link from any model element back to its parent semantic model." ; rdfs:range obsl:SemanticModel . # ============================================================================= # 3. OBJECT PROPERTIES --- Data object structure # ============================================================================= obsl:hasColumn a owl:ObjectProperty ; rdfs:label "has column" ; rdfs:comment "Links a data object to one of its columns." ; rdfs:domain obsl:DataObject ; rdfs:range obsl:Column . obsl:hasJoin a owl:ObjectProperty ; rdfs:label "has join" ; rdfs:comment "Links a data object to a join path originating from it." ; rdfs:domain obsl:DataObject ; rdfs:range obsl:Join . obsl:joinTo a owl:ObjectProperty ; rdfs:label "join to" ; rdfs:comment "Target data object of a join path." ; rdfs:domain obsl:Join ; rdfs:range obsl:DataObject . obsl:columnFrom a owl:ObjectProperty ; rdfs:label "column from" ; rdfs:comment "Source column (in the originating data object) used in the join condition." ; rdfs:domain obsl:Join ; rdfs:range obsl:Column . obsl:columnTo a owl:ObjectProperty ; rdfs:label "column to" ; rdfs:comment "Target column (in the joined data object) used in the join condition." ; rdfs:domain obsl:Join ; rdfs:range obsl:Column . # ============================================================================= # 4. OBJECT PROPERTIES --- Dimension, measure & metric references # ============================================================================= obsl:dataObject a owl:ObjectProperty ; rdfs:label "data object" ; rdfs:comment "Data object that a dimension draws its values from." ; rdfs:range obsl:DataObject . obsl:column a owl:ObjectProperty ; rdfs:label "column" ; rdfs:comment "Column that a dimension or measure is bound to." ; rdfs:range obsl:Column . obsl:sourceColumn a owl:ObjectProperty ; rdfs:label "source column" ; rdfs:comment "Column that a measure aggregates over (when the measure is column-based, not expression-based)." ; rdfs:domain obsl:Measure ; rdfs:range obsl:Column . obsl:baseMeasure a owl:ObjectProperty ; rdfs:label "base measure" ; rdfs:comment "Measure that a cumulative metric is computed from (used when metricType is cumulative)." ; rdfs:domain obsl:Metric ; rdfs:range obsl:Measure . obsl:referencesMeasure a owl:ObjectProperty ; rdfs:label "references measure" ; rdfs:comment "Measure referenced in a metric's expression. A metric may reference multiple measures." ; rdfs:domain obsl:Metric ; rdfs:range obsl:Measure . obsl:timeDimension a owl:ObjectProperty ; rdfs:label "time dimension" ; rdfs:comment "Dimension used as the time axis for cumulative or period-over-period metrics." ; rdfs:domain obsl:Metric ; rdfs:range obsl:Dimension . # ============================================================================= # 5. DATATYPE PROPERTIES --- Identifiers & physical mapping # ============================================================================= obsl:code a owl:DatatypeProperty ; rdfs:label "code" ; rdfs:comment "Machine-readable identifier or physical name (e.g., SQL column name, table name)." ; rdfs:range xsd:string . obsl:database a owl:DatatypeProperty ; rdfs:label "database" ; rdfs:comment "Database or catalog name where the data object resides." ; rdfs:range xsd:string . obsl:schema a owl:DatatypeProperty ; rdfs:label "schema" ; rdfs:comment "Database schema containing the data object." ; rdfs:range xsd:string . obsl:physicalName a owl:DatatypeProperty ; rdfs:label "physical name" ; rdfs:comment "Physical SQL name when it differs from the code value." ; rdfs:range xsd:string . # ============================================================================= # 6. DATATYPE PROPERTIES --- Types, aggregation & expressions # ============================================================================= obsl:resultType a owl:DatatypeProperty ; rdfs:label "result type" ; rdfs:comment "Abstract data type of the value: string, int, float, date, time, timestamp, boolean, json, time_tz, timestamp_tz." ; rdfs:range xsd:string . obsl:aggregation a owl:DatatypeProperty ; rdfs:label "aggregation" ; rdfs:comment "Aggregation function applied to the measure: sum, count, count_distinct, avg, min, max, any_value, median, mode, listagg." ; rdfs:range xsd:string . obsl:metricType a owl:DatatypeProperty ; rdfs:label "metric type" ; rdfs:comment "Kind of metric calculation: derived, cumulative, period_over_period." ; rdfs:range xsd:string . obsl:cardinality a owl:DatatypeProperty ; rdfs:label "cardinality" ; rdfs:comment "Join cardinality between data objects: many-to-one, one-to-one, many-to-many." ; rdfs:range xsd:string . obsl:timeGrain a owl:DatatypeProperty ; rdfs:label "time grain" ; rdfs:comment "Time granularity. On dimensions: default grain. On period-over-period metrics: comparison grain." ; rdfs:range xsd:string . obsl:expressionSource a owl:DatatypeProperty ; rdfs:label "expression source" ; rdfs:comment "Expression string defining a calculated measure or metric. Measures use {[DataObject].[Column]} syntax; metrics use {[Measure Name]} syntax." ; rdfs:range xsd:string . obsl:filterExpression a owl:DatatypeProperty ; rdfs:label "filter expression" ; rdfs:comment "Human-readable expression string describing the measure's filter conditions (e.g. \"Customers.Country equals 'US'\"). Serialized from structured OBML measure filters." ; rdfs:domain obsl:Measure ; rdfs:range xsd:string . # ============================================================================= # 7. DATATYPE PROPERTIES --- Behavioral flags # ============================================================================= obsl:secondary a owl:DatatypeProperty ; rdfs:label "secondary" ; rdfs:comment "When true, marks a join as a secondary join path (not the default path between two data objects)." ; rdfs:range xsd:boolean . obsl:pathName a owl:DatatypeProperty ; rdfs:label "path name" ; rdfs:comment "Named join path used when a dimension reaches its data object through a non-default route." ; rdfs:range xsd:string . obsl:synonym a owl:DatatypeProperty ; rdfs:label "synonym" ; rdfs:comment "Alternative name for an element, used for natural-language search and LLM disambiguation." ; rdfs:range xsd:string . obsl:distinct a owl:DatatypeProperty ; rdfs:label "distinct" ; rdfs:comment "When true, the measure applies DISTINCT to its aggregation (e.g., COUNT DISTINCT)." ; rdfs:range xsd:boolean . obsl:total a owl:DatatypeProperty ; rdfs:label "total" ; rdfs:comment "When true, the measure computes a grand total across all dimension values (ignores GROUP BY)." ; rdfs:range xsd:boolean . obsl:allowFanOut a owl:DatatypeProperty ; rdfs:label "allow fan-out" ; rdfs:comment "When true, permits this measure to be queried along fan-out join paths (bypasses fan-trap prevention)." ; rdfs:range xsd:boolean . # ============================================================================= # 8. DATATYPE PROPERTIES --- Cumulative & period-over-period metrics # ============================================================================= obsl:cumulativeType a owl:DatatypeProperty ; rdfs:label "cumulative type" ; rdfs:comment "Aggregation function for the cumulative window: sum, avg, min, max, count." ; rdfs:domain obsl:CumulativeMetric ; rdfs:range xsd:string . obsl:window a owl:DatatypeProperty ; rdfs:label "window" ; rdfs:comment "Rolling window size in periods for a cumulative metric. Absent means unbounded (running total)." ; rdfs:domain obsl:CumulativeMetric ; rdfs:range xsd:integer . obsl:grainToDate a owl:DatatypeProperty ; rdfs:label "grain to date" ; rdfs:comment "Grain-to-date reset boundary for a cumulative metric: year, quarter, month, week. Mutually exclusive with window." ; rdfs:domain obsl:CumulativeMetric ; rdfs:range xsd:string . obsl:offset a owl:DatatypeProperty ; rdfs:label "offset" ; rdfs:comment "Period offset for a period-over-period comparison (typically -1)." ; rdfs:domain obsl:PeriodOverPeriodMetric ; rdfs:range xsd:integer . obsl:offsetGrain a owl:DatatypeProperty ; rdfs:label "offset grain" ; rdfs:comment "Grain of the offset period: day, week, month, quarter, year." ; rdfs:domain obsl:PeriodOverPeriodMetric ; rdfs:range xsd:string . obsl:comparison a owl:DatatypeProperty ; rdfs:label "comparison" ; rdfs:comment "Comparison type for a period-over-period metric: ratio, difference, previousValue, percentChange." ; rdfs:domain obsl:PeriodOverPeriodMetric ; rdfs:range xsd:string . # ============================================================================= # 9. OWL AXIOMS # ============================================================================= # ----------------------------------------------------------------------------- # 9.1 Class disjointness — core classes are mutually exclusive # ----------------------------------------------------------------------------- [] a owl:AllDisjointClasses ; owl:members ( obsl:SemanticModel obsl:DataObject obsl:Column obsl:Join obsl:Dimension obsl:Measure obsl:Metric ) . # Metric subtypes are disjoint with each other. obsl:CumulativeMetric owl:disjointWith obsl:PeriodOverPeriodMetric . # ----------------------------------------------------------------------------- # 9.2 Functional properties — at most one value # ----------------------------------------------------------------------------- # Properties that SHACL constrains to sh:maxCount 1 are also declared # owl:FunctionalProperty so that OWL-aware tools can enforce cardinality # without loading the SHACL shapes. obsl:joinTo a owl:FunctionalProperty . obsl:code a owl:FunctionalProperty . obsl:database a owl:FunctionalProperty . obsl:schema a owl:FunctionalProperty . obsl:physicalName a owl:FunctionalProperty . obsl:resultType a owl:FunctionalProperty . obsl:aggregation a owl:FunctionalProperty . obsl:metricType a owl:FunctionalProperty . obsl:cardinality a owl:FunctionalProperty . obsl:expressionSource a owl:FunctionalProperty . obsl:filterExpression a owl:FunctionalProperty . obsl:dataObject a owl:FunctionalProperty . obsl:column a owl:FunctionalProperty . obsl:cumulativeType a owl:FunctionalProperty . obsl:window a owl:FunctionalProperty . obsl:grainToDate a owl:FunctionalProperty . obsl:offset a owl:FunctionalProperty . obsl:offsetGrain a owl:FunctionalProperty . obsl:comparison a owl:FunctionalProperty . # ----------------------------------------------------------------------------- # 9.3 Inverse properties # ----------------------------------------------------------------------------- # belongsToModel is the inverse of the four has* composition properties. # Since OWL inverseOf is per-property, belongsToModel is declared inverse # of hasDataObject; the other has* links share the same semantic intent # but would require a union-property pattern to formalize further. obsl:belongsToModel owl:inverseOf obsl:hasDataObject .