ISO/IEC 9075-16:2023/Cor 1:2026

• Status: Published
• Publication Date: 02-Aug-2026
• ICS: 35.060 - Languages used in information technology
• Technical Committee: ISO/IEC JTC 1/SC 32 - Data management and interchange
• Drafting Committee: ISO/IEC JTC 1/SC 32/WG 3 - Database language
• Current Stage: 6060 - International Standard published
• Start Date: 03-Aug-2026
• Completion Date: 03-Aug-2026

• Corrects: ISO/IEC 9075-16:2023 - Information technology — Database languages SQL — Part 16: Property Graph Queries (SQL/PGQ)
• Effective Date: 07-Jan-2026

ISO/IEC 9075-16:2023/Cor.1:2026 is ISO’s Technical Corrigendum 1 to SQL Part 16, Property Graph Queries (SQL/PGQ). It corrects and refines the language rules for property graph queries, especially label handling, path matching, descriptor creation, and conformance features. It is mainly for database implementers, test writers, and anyone checking SQL/PGQ conformance.

What does ISO/IEC 9075-16:2023/Cor.1:2026 specify?

ISO/IEC 9075-16:2023/Cor.1:2026 specifies targeted corrections to the SQL/PGQ text in clauses 4, 6, 8, 9, 10, and 18. In practice, it updates definitions, syntax rules, general rules, notes, and conformance relationships so implementations interpret SQL/PGQ consistently.

The document is organized as a set of clause-by-clause replacements and insertions, plus an update to the implied feature relationships in Table 5. The affected areas are:

• Clause 4.5 - SQL-propertygraphs and Purepropertygraph
• Clause 6 - Scalar expressions
• Clause 8.4 - <source/destinationpredicate>
• Clause 9 - Additional common rules
• Clause 10 - Additional common elements
• Clause 18.3 - Implied feature relationships of SQL/PGQ

What are the key requirements of ISO/IEC 9075-16:2023/Cor.1:2026?

ISO/IEC 9075-16:2023/Cor.1:2026 mainly tightens how labels, equality, path matching, and feature dependencies are handled. The practical effect is to remove ambiguities that could change query behavior or conformance checking.

Label sets and property graph descriptors

Clause 4.5 corrects the wording around pure property graph structures. It distinguishes directed and undirected edge triplets and ties them to source, destination, or endpoint vertex defined label sets. For implementers, this matters when deriving a pure property graph descriptor from a tabular property graph descriptor.

Clause 9.16 also corrects how a pure property graph descriptor is derived from a tabular property graph descriptor. It states that vertex defined label sets come from the labels of each vertex table, and that edge triplets are built from the labels associated with each edge table and its source and destination vertex tables.

Equality and descriptor checks

Clause 9.0 adds missing cases to the definition of equality operations. It brings edge table definitions and certain key-clause columns into the rules for operands of equality operations. In practice, this means the standard now explicitly covers the equality checks used when comparing descriptor columns.

Clause 9.14 reinforces that descriptor key columns must be compared pairwise and that corresponding declared types must be comparable. Clause 9.15 adds a collation requirement for character string properties. These rules matter because they control whether a graph descriptor can be accepted as consistent.

Predicates and label expressions

Clause 8.4 tightens the conformance rule for ISSOURCE and ISDESTINATION predicates when Feature G112 is absent. This helps vendors know exactly which predicate forms are allowed in a conforming SQL language implementation.

Clause 10.8 corrects how a is resolved when it appears in different places, including a or a . It also ties label names to the vertex defined label sets or edge defined label sets in the pure property graph descriptor. That matters because label references must match the graph model being queried.

Graph pattern matching and path evaluation

Clauses 9.6 and 9.7 adjust the rules and notes for path bindings, annotated paths, and evaluation of . They also account for and explain when potentially infinite intermediate sets are reduced to finite results. In practice, these changes guide implementations toward predictable path-query evaluation.

Clause 10.4 updates rules so the correct sets are produced when selective path patterns and different edges match mode are involved. Clause 10.6 revises a note about effect of effectively unbounded group variables. Together, these corrections matter for shortest-path and repeated-edge query behavior.

Feature dependencies

Clause 18.3 extends Table 5 with additional implied feature relationships for SQL/PGQ. The added rows cover features such as explicit WALK, advanced path modes, explicit PATH/PATHS keywords, all path search, any path search, shortest path search, and GRAPH_TABLE-related features. This helps conformance checkers determine which features must be supported together.

What terms does ISO/IEC 9075-16:2023/Cor.1:2026 define?

ISO/IEC 9075-16:2023/Cor.1:2026 uses several graph-specific terms that are central to the corrections.

• SQL/PGQ - SQL Property Graph Queries, the SQL language extension covered by Part 16.
• Pure property graph - the graph form used in the corrected label and edge-triplet rules.
• Pure property graph descriptor (PPGD) - the descriptor that represents the pure property graph and its label sets.
• Tabular property graph descriptor (TPGD) - the descriptor from which a pure property graph descriptor is derived.
• Path binding - a sequence of elementary bindings used in graph pattern matching.
• Different edges match mode - a matching mode that affects how graph pattern results are formed and bounded.
• Edge triplet - the edge-related label-set structure used in the pure property graph descriptor.
• ISSOURCE and ISDESTINATION predicate - predicates whose allowed use is clarified by the corrigendum.

Who uses ISO/IEC 9075-16:2023/Cor.1:2026?

ISO/IEC 9075-16:2023/Cor.1:2026 is used by database engine developers, standards implementers, and conformance test writers working on SQL/PGQ support. It also helps quality teams, product managers, and buyers who need to verify that a database claims the right graph-query features. In practice, these users apply it when designing parsers, query evaluators, metadata checks, and feature conformance tests.

What changed in ISO/IEC 9075-16:2023/Cor.1:2026 from the previous edition?

ISO/IEC 9075-16:2023/Cor.1:2026 is a technical corrigendum to ISO/IEC 9075-16:2023. It corrects terminology, syntax-rule wording, conformance rules, and feature relationships in clauses 4, 6, 8, 9, 10, and 18.

Which standards are used with ISO/IEC 9075-16:2023/Cor.1:2026?

ISO/IEC 9075-16:2023 is the base standard that this corrigendum amends. ISO/IEC 9075-2 is named in clause 9.0, where the equality operations rules are stated to modify subclause 9.11 of that part. That link matters because some graph-query rules inherit core SQL equality behavior from Part 2.

What does the ISO/IEC 9075-16:2023/Cor.1:2026 document contain?

ISO/IEC 9075-16:2023/Cor.1:2026 contains replacement text for selected syntax rules, general rules, notes, and conformance rules rather than a full rewrite of SQL/PGQ. It also adds a new subclause for equality operations and updates the implied feature relationship table in Clause 18.

The document includes corrections for label resolution, descriptor derivation, path pattern evaluation, and graph-pattern matching. It also updates the text used for feature dependency checks, which is important for certification and implementation testing.

International
Standard
ISO/IEC 9075-16
First edition
Information technology — Database
2023-06
languages SQL —
TECHNICAL
Part 16:
CORRIGENDUM 1
Property Graph Queries (SQL/PGQ)
2026-08
TECHNICAL CORRIGENDUM 1
Reference number
ISO/IEC 9075-16:2023/Cor. 1:2026(en) © ISO/IEC 2026

ISO/IEC 9075-16:2023/Cor. 1:2026(en)
© ISO/IEC 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ISO copyright office
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Phone: [phone]
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Published in Switzerland
© ISO/IEC 2026 – All rights reserved
ii
or. 1:2026(en)
ISO/IEC 9075-16:2023/Cor.1:2026(en)
Technical Corrigendum 1 to ISO/IEC 9075-16:2023 was prepared by Joint Technical Committee ISO/IEC JTC
1, Information technology, Subcommittee SC 32, Data management and interchange.
© ISO/IEC 2026 – All rights reserved
iii
ISO/IEC 9075-16:2023/Cor. 1:2026(en)
4 Concepts
4.5 SQL-propertygraphs
4.5 Purepropertygraph
1. Rationale: Correcttheuseoftermsrelatedtolabels.
Replacethesecondsubitemofthefourthitemofthesecondparagraphwith:
— .
— .
— .
— .
• .
• Anindicationwhethertheedgetripletdescribesdirectededgesorundirectededges.
Case:
— Iftheedgetripletdescribesdirectededges,then:
• asourcevertexdefinedlabelset,whichisasubsetofavertexdefinedlabel
set;
• adestinationvertexdefinedlabelset,whichisasubsetofavertexdefined
labelset.
— Iftheedgetripletdescribesundirectededges,then:
• apairofendpointvertexdefinedlabelsets,eachofwhichisasubsetofa
vertexdefinedlabelset.
6 Scalarexpressions
6
1. Rationale: AugmentthecorrectRule.
ReplaceSyntaxRule2)with:
2) AugmentSR8) byadding“apropertyPR”tothelistofpossiblereferentsofabasis.
©ISO/IEC2026–Allrightsreserved
ISO/IEC 9075-16:2023/Cor. 1:2026(en)
8 Predicates
8.4
1. Rationale: CorrectthescopeofaConformanceRule.
ReplaceConformnaceRule1)with:
1) WithoutFeatureG112,“ISSOURCEandISDESTINATIONpredicate”,conformingSQLlanguage
shallnotcontaina,ora.
9 Additionalcommonrules
9.0 Equalityoperations
1. Rationale: Addmissingitemstodefinitionsof“equalityoperation”and“operandofanequalityoperation”
InsertanewSubclause
9.0 Equalityoperations
ThisSubclausemodifiesSubclause9.11,“Equalityoperations”,inISO/IEC9075-2.
Function
Specifytheprohibitionsandrestrictionsbydatatypeonoperationsthatinvolvetestingforequality.
SyntaxRules
1) InsertafterSR1)i): An.
2) InsertafterSR2)m):Acolumnofa,acolumnofa vertextablekeyclause>,oracolumnofa.
AccessRules
NoadditionalAccessRules.
GeneralRules
NoadditionalGeneralRules.
ConformanceRules
NoadditionalConformanceRules.
©ISO/IEC2026–Allrightsreserved
ISO/IEC 9075-16:2023/Cor. 1:2026(en)
9.6 Machineryforgraphpatternmatching
1. Rationale: Replaceundefinedsymbolwithdefinedsymbol.
ReplacetheleadtextofGeneralRule13)with:
13) Apathbindingisasequenceofzeroormoreelementarybindings,B=(LET,GE),.,(LET ,
1 1 N
GE ).GivenapathbindingB:
N
2. Rationale: Replaceundefinedsymbolwithdefinedsymbol.
ReplaceGeneralRule13)b)with:
13) .
b) TheannotatedpathofBisthesequenceGE,.,GE .
1 N
3. Rationale: Replaceundefinedsymbolwithdefinedsymbol.
ReplaceGeneralRule16)b)with:
16) .
b) Foreverytwovertexbindings(LET,GE)and(LET,GE)thatarenotseparable,GE
1 1 2 2 1
=GE.
4. Rationale: Takeaccountofthe.
ReplaceNote76with:
*
NOTE76—IfSisnotempty,thenS isaninfiniteset;however,afiniteresultforeveryisassured
bythesyntacticrequirementthateveryisbounded,containedinarestrictive pathpatternexpression>,containedinaselective,orinthescopeofthe.
9.7 Evaluationofa
1. Rationale: Takeaccountofthe.
ReplaceNote78with:
NOTE78—RL(BNT)andSLM(BNT)canbeinfinitesetsifBNTcontainsaneffectivelyunboundedquantifier.Every
effectivelyunboundedquantifierisrequiredtobeeithercontainedinaselectiveorinthescopeofthe
.Foraselective,thepotentiallyinfinitesetoflocalmatchesissubsequently
reducedtoafinitesetbytheGeneralRulesofSubclause9.8,“Evaluationofaselective”.For edgesmatchmode>,thematchesarereducedtoafinitesetbytheGeneralRulesofSubclause10.4,“”.
9.14 Creationofanedgetabledescriptor
1. Rationale: Ensurethattherulesforequalityanddeclaredtypearechecked.
InsertthefollowingSyntaxRules:
9) .
©ISO/IEC2026–Allrightsreserved
ISO/IEC 9075-16:2023/Cor. 1:2026(en)
b) .
iii) EachcolumninESKanditscorrespondingcolumninSVKareoperandsofan
equalityoperation.TheSyntaxRulesandConformanceRulesofSubclause9.0,
“Equalityoperations”,apply.
iv) ESKshallcontainthesamenumberNCNofsasSVK.For1(one)
≤i≤NCN,thei-thcolumn,identifiedinESKcorrespondstothei-thcolumn
identifiedinSVK.ThedeclaredtypeofeachcolumninESKshallbecomparable
tothedeclaredtypeofthecorrespondingcolumninSVK.
2. Rationale: Ensurethattherulesforequalityanddeclaredtypearechecked.
InsertthefollowingSyntaxRules:
10) .
b) .
iii) EachcolumninEDKanditscorrespondingcolumninDVKareoperandsofan
equalityoperation.TheSyntaxRulesandConformanceRulesofSubclause9.0,
“Equalityoperations”,apply.
iv) EDKshallcontainthesamenumberNCNofsasDVK.For1(one)
≤i≤NCN,thei-thcolumn,identifiedinEDKcorrespondstothei-thcolumn
identifiedinDVK.ThedeclaredtypeofeachcolumninEDKshallbecomparable
tothedeclaredtypeofthecorrespondingcolumninDVK.
9.15 Consistencycheckofatabularpropertygraphdescriptor
1. Rationale: Ensurethatallcharacterstringpropertieshaveacollation.
InsertthefollowingSyntaxRules:
4) .
c) .
iii) .
1.0) IfthedeclaredtypeofPisacharacterstringtype,thenPshallhavea
declaredtypecollation.
...