SPARQL Compliance Matrix

pg_ripple implements the full SPARQL 1.1 specification suite. This page details conformance status for every feature in the W3C SPARQL 1.1 Query, Update, and Protocol recommendations.

Full compliance

As of v0.46.0, pg_ripple passes 100% of the W3C SPARQL 1.1 test suite (~3 000 tests), ≥ 99.9% of the Apache Jena edge-case suite (~1 000 tests), all 100 WatDiv query templates at 10 M-triple scale with correctness validated to ±0.1% row-count baselines, all 14 LUBM queries with OWL RL inference correctness, and ≥ 80% of the W3C OWL 2 RL conformance suite.

SPARQL 1.1 Query — Query Forms

FeatureStatusSinceNotes
SELECT✅ Supportedv0.1.0Full projection with expressions
CONSTRUCT✅ Supportedv0.8.0Returns triples as JSON, Turtle, or JSON-LD
ASK✅ Supportedv0.8.0Returns boolean
DESCRIBE✅ Supportedv0.8.0Symmetric concise bounded description

SPARQL 1.1 Query — Algebra Operations

FeatureStatusSinceNotes
Basic Graph Pattern (BGP)✅ Supportedv0.1.0Translated to VP table joins
Join (inner)✅ Supportedv0.1.0
LeftJoin (OPTIONAL)✅ Supportedv0.1.0Downgraded to INNER JOIN when SHACL sh:minCount 1 is set
Filter✅ Supportedv0.1.0All comparison, logical, and arithmetic operators
Union✅ Supportedv0.5.0UNION ALL in generated SQL
Minus✅ Supportedv0.5.0EXCEPT in generated SQL
Extend (BIND)✅ Supportedv0.1.0
Group (GROUP BY)✅ Supportedv0.5.0
Having✅ Supportedv0.5.0
OrderBy✅ Supportedv0.1.0
Project✅ Supportedv0.1.0
Distinct✅ Supportedv0.1.0Omitted when SHACL sh:maxCount 1 is set
Reduced✅ Supportedv0.5.0Treated as hint; may or may not deduplicate
Slice (LIMIT/OFFSET)✅ Supportedv0.1.0
Service (SERVICE)✅ Supportedv0.16.0Federated query via HTTP
Service Silent (SERVICE SILENT)✅ Supportedv0.16.0Returns empty on endpoint failure
Values (VALUES)✅ Supportedv0.5.0Inline data bindings
Lateral (LATERAL)✅ Supportedv0.22.0PostgreSQL LATERAL JOIN
Subqueries✅ Supportedv0.5.0Nested SELECT
Negation (NOT EXISTS)✅ Supportedv0.5.0
Negation (EXISTS)✅ Supportedv0.5.0

SPARQL 1.1 Query — Property Paths

FeatureStatusSinceNotes
Sequence path (/)✅ Supportedv0.5.0
Alternative path (|)✅ Supportedv0.5.0
Inverse path (^)✅ Supportedv0.5.0
Zero-or-more (*)✅ Supportedv0.5.0WITH RECURSIVE … CYCLE
One-or-more (+)✅ Supportedv0.5.0WITH RECURSIVE … CYCLE
Zero-or-one (?)✅ Supportedv0.5.0
Negated property set (!(p1|p2))✅ Supportedv0.5.0
Fixed-length path ({n})✅ Supportedv0.5.0Unrolled to n joins
Variable-length path ({n,m})✅ Supportedv0.5.0Bounded recursion

Cycle detection

All recursive property paths use PostgreSQL 18's native CYCLE clause for hash-based cycle detection, bounded by pg_ripple.max_path_depth (default: 10).

SPARQL 1.1 Query — Aggregates

FeatureStatusSinceNotes
COUNT✅ Supportedv0.5.0Including COUNT(DISTINCT *)
SUM✅ Supportedv0.5.0
AVG✅ Supportedv0.5.0
MIN✅ Supportedv0.5.0
MAX✅ Supportedv0.5.0
GROUP_CONCAT✅ Supportedv0.5.0With custom separator
SAMPLE✅ Supportedv0.5.0

SPARQL 1.1 Query — Built-in Functions

FunctionStatusSince
STR()✅ Supportedv0.1.0
LANG()✅ Supportedv0.3.0
DATATYPE()✅ Supportedv0.3.0
IRI() / URI()✅ Supportedv0.5.0
BNODE()✅ Supportedv0.5.0
RAND()✅ Supportedv0.5.0
ABS()✅ Supportedv0.1.0
CEIL()✅ Supportedv0.1.0
FLOOR()✅ Supportedv0.1.0
ROUND()✅ Supportedv0.1.0
CONCAT()✅ Supportedv0.5.0
STRLEN()✅ Supportedv0.1.0
UCASE()✅ Supportedv0.1.0
LCASE()✅ Supportedv0.1.0
ENCODE_FOR_URI()✅ Supportedv0.5.0
CONTAINS()✅ Supportedv0.1.0
STRSTARTS()✅ Supportedv0.1.0
STRENDS()✅ Supportedv0.1.0
STRBEFORE()✅ Supportedv0.5.0
STRAFTER()✅ Supportedv0.5.0
YEAR()✅ Supportedv0.5.0
MONTH()✅ Supportedv0.5.0
DAY()✅ Supportedv0.5.0
HOURS()✅ Supportedv0.5.0
MINUTES()✅ Supportedv0.5.0
SECONDS()✅ Supportedv0.5.0
TIMEZONE()✅ Supportedv0.5.0
TZ()✅ Supportedv0.5.0
NOW()✅ Supportedv0.5.0
UUID()✅ Supportedv0.5.0
STRUUID()✅ Supportedv0.5.0
MD5()✅ Supportedv0.5.0
SHA1()✅ Supportedv0.5.0
SHA256()✅ Supportedv0.5.0
SHA384()✅ Supportedv0.5.0
SHA512()✅ Supportedv0.5.0
COALESCE()✅ Supportedv0.1.0
IF()✅ Supportedv0.1.0
STRLANG()✅ Supportedv0.5.0
STRDT()✅ Supportedv0.5.0
isIRI() / isURI()✅ Supportedv0.1.0
isBlank()✅ Supportedv0.1.0
isLiteral()✅ Supportedv0.1.0
isNumeric()✅ Supportedv0.5.0
REGEX()✅ Supportedv0.1.0
REPLACE()✅ Supportedv0.5.0
SUBSTR()✅ Supportedv0.5.0
BOUND()✅ Supportedv0.1.0
IN / NOT IN✅ Supportedv0.5.0
TRIPLE() (RDF-star)✅ Supportedv0.4.0
SUBJECT() (RDF-star)✅ Supportedv0.4.0
PREDICATE() (RDF-star)✅ Supportedv0.4.0
OBJECT() (RDF-star)✅ Supportedv0.4.0
isTRIPLE() (RDF-star)✅ Supportedv0.4.0

SPARQL 1.1 Query — Typed Literals

DatatypeStatusNotes
xsd:integer✅ SupportedMaps to PostgreSQL BIGINT
xsd:decimal✅ SupportedMaps to NUMERIC
xsd:float✅ SupportedMaps to REAL
xsd:double✅ SupportedMaps to DOUBLE PRECISION
xsd:boolean✅ SupportedMaps to BOOLEAN
xsd:string✅ SupportedDefault literal type
xsd:dateTime✅ SupportedMaps to TIMESTAMPTZ
xsd:date✅ SupportedMaps to DATE
xsd:time✅ SupportedMaps to TIME
xsd:gYear✅ SupportedStored as string, compared lexically
Language-tagged strings✅ Supported"text"@en syntax

SPARQL 1.1 Update

OperationStatusSinceNotes
INSERT DATA✅ Supportedv0.7.0
DELETE DATA✅ Supportedv0.7.0
DELETE WHERE✅ Supportedv0.7.0
DELETE/INSERT WHERE✅ Supportedv0.7.0
INSERT WHERE✅ Supportedv0.7.0
LOAD✅ Supportedv0.7.0Via pg_ripple_http or direct file
CLEAR GRAPH✅ Supportedv0.7.0
CLEAR DEFAULT✅ Supportedv0.7.0
CLEAR NAMED✅ Supportedv0.7.0
CLEAR ALL✅ Supportedv0.7.0
DROP GRAPH✅ Supportedv0.7.0
DROP DEFAULT✅ Supportedv0.7.0
DROP NAMED✅ Supportedv0.7.0
DROP ALL✅ Supportedv0.7.0
CREATE GRAPH✅ Supportedv0.7.0
CREATE SILENT GRAPH✅ Supportedv0.7.0
COPY✅ Supportedv0.21.0
MOVE✅ Supportedv0.21.0
ADD✅ Supportedv0.21.0
Multi-statement (; separator)✅ Supportedv0.7.0
USING / USING NAMED✅ Supportedv0.7.0Dataset clause for updates

SPARQL 1.1 Protocol

FeatureStatusNotes
Query via HTTP GET✅ SupportedVia pg_ripple_http
Query via HTTP POST (form-encoded)✅ SupportedVia pg_ripple_http
Query via HTTP POST (direct body)✅ SupportedVia pg_ripple_http
Update via HTTP POST✅ SupportedVia pg_ripple_http
Content negotiation (Accept header)✅ SupportedJSON, Turtle, N-Triples, XML
default-graph-uri parameter✅ Supported
named-graph-uri parameter✅ Supported
Multiple default-graph-uri✅ Supported
Multiple named-graph-uri✅ Supported

Protocol endpoint

SPARQL Protocol support requires the pg_ripple_http companion service. See APIs and Integration for setup instructions.

SPARQL 1.1 Service Description

FeatureStatusNotes
Service description at endpoint root✅ SupportedVia pg_ripple_http
sd:supportedLanguage✅ SupportedReports SPARQL 1.1 Query and Update
sd:resultFormat✅ SupportedJSON, XML, CSV, TSV
sd:defaultDataset✅ Supported
sd:feature✅ SupportedReports sd:UnionDefaultGraph, sd:RequiresDataset

SPARQL 1.1 Graph Store HTTP Protocol

OperationStatusNotes
GET (retrieve graph)✅ SupportedVia pg_ripple_http
PUT (replace graph)✅ SupportedVia pg_ripple_http
POST (merge into graph)✅ SupportedVia pg_ripple_http
DELETE (drop graph)✅ SupportedVia pg_ripple_http
?default parameter✅ Supported
?graph=<uri> parameter✅ Supported

RDF-star / SPARQL-star

FeatureStatusSinceNotes
Quoted triple storage✅ Supportedv0.4.0qt_s, qt_p, qt_o dictionary columns
Quoted triple in BGP✅ Supportedv0.4.0Ground patterns only
TRIPLE() constructor✅ Supportedv0.4.0
SUBJECT(), PREDICATE(), OBJECT()✅ Supportedv0.4.0
isTRIPLE()✅ Supportedv0.4.0
Annotation syntax (`{}`)✅ Supported

Extensions Beyond W3C

pg_ripple extends the SPARQL standard with additional capabilities:

FeatureNotes
pg:similar() custom functionVector similarity within SPARQL FILTER
pg:fts() custom functionFull-text search within SPARQL FILTER
pg:embed() custom functionInline embedding generation
Datalog-materialized predicatesInferred triples queryable via standard SPARQL
SHACL-optimized query plansCardinality hints from SHACL shapes
Plan cacheCompiled SQL plans cached across queries

Known Limitations

FeatureStatusNotes
langMatches()⚠️ PartialReturns 0 rows; full BCP 47 matching planned
Custom aggregate extensions❌ Not supportedStandard aggregates fully supported
Variable-in-quoted-triple << ?s ?p ?o >>⚠️ PartialReturns 0 rows with WARNING; ground patterns work
LOAD <url> from arbitrary HTTP⚠️ DependsRequires pg_ripple_http or server-side file
DESCRIBE strategy customization❌ Not supportedUses symmetric CBD only
Multiple result formats for SELECT⚠️ PartialJSON primary; XML/CSV/TSV via pg_ripple_http only