International IEC ISO Standard IS0/IEC39075 Information technology Database First edition languages GQL 2024-04 Technologies de I'information - Langages de base de données - GQL Reference number IS0/IEC 39075:2024(en) @ ISO/IEC 2024 IS0/IEC 39075:2024(en) COPYRIGHT PROTECTED DOCUMENT IS0/IEC2024 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below orIso'smemberbodyinthecountryoftherequester. ISo copyright office CP 40i: Ch.de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland @IS0/IEC 2024 - All rights reserved ii IS0/IEC 39075:2024(en) Contents Page Foreword.. . xiv Introduction. XV 1 Scope.. 2 Normative references. 3 Terms and definitions. 3.1 General terms and definitions. 3.2 GQL-environment terms and definitions. . 3.3 GQL-catalog terms and definitions. . . 3.4 Graph terms and definitions. . . 3.5 Procedure and command terms and definitions. . 3.6 General syntax terms and definitions. . . 12 3.7 Graph pattern terms and definitions. . 14 3.8 Value terms and definitions. . 15 3.9 Type terms and definitions. . . 3.10 Temporal terms and definitions. . . 19 4 Concepts.. .21 4.1 Use of terms. . 4.2 GQL-environments and their components 4.2.1 General description of GQL-environments. 4.2.2 GQL-agents. 4.2.3 GQL-implementations. 22 4.2.3.1 Introduction to GQL-implementations. . 22 4.2.3.2 GQL-clients. 4.2.3.3 GQL-servers. 23 4.2.4 Basic security model. . 24 4.2.4.1 Principals. . . 24 4.2.4.2 Authorization identifiers and privileges. 24 4.2.5 GQL-catalog. .. .24 4.2.5.1 General description of the GQL-catalog. . . 4.2.5.2 GQL-directories... ..25 4.2.5.3 GQL-schemas.... 4.2.6 GQL-data... ...27 4.3 GQL-objects.. ...27 4.3.1 General introductionto GQL-objects. 4.3.2 ReferencestoGQL-schemasandGQL-objects. 4.3.3 Primary objects and secondary objects. . ..28 4.3.4 Properties and supported property value types. ..28 4.3.5 Graphs.... .29 @ IS0/IEC 2024 - All rights reserved iii IS0/IEC 39075:2024(en) 4.3.5.1 Introduction to graphs. 29 4.3.5.2 Graph descriptors. . 30 4.3.6 Binding tables. . 4.4 4.4.1 General information about values. 4.4.2 Comparable values. . . . 4.4.3 Properties of distinct values. 4.4.4 Reference values. 4.4.5 Material values and the null value. . 4.5 GQL-sessions. 4.5.1 General description of GQL-sessions. .33 4.5.2 Session contexts. .34 4.5.2.1 Introduction to session contexts. .34 4.5.2.2 Session context creation. .35 4.5.2.3 Session context modification. 35 4.6 GQL-transactions. 35 4.6.1 General description of GQL-transactions. 35 4.6.2 Transaction demarcation. . 36 4.6.3 Transaction isolation. . 4.6.4 Encompassing transaction belonging to an external agent. 37 4.7 GQL-requests and GQL-programs. . 38 4.7.1 General description of GQL-requests and GQL-programs. 38 4.7.2 GQL-request contexts. . . 38 4.7.2.1 Introduction to GQL-request contexts. .38 4.7.2.2 GQL-request context creation. . . ..38 4.7.2.3 GQL-request context modification. 4.7.3 ExecutionofGQL-requests... 4.7.4 Working schema references. . . ...40 4.7.5 Working graph site. . . . ...41 4.7.6 Execution stack. 4.7.7 Operations. 4.8 Execution contexts. 4.8.1 General description of execution contexts. 4.8.2 Execution context creation and initialization. .44 4.8.3 Execution context modification. . .45 4.8.4 Execution outcomes.. 45 4.9 Diagnostic information. . .46 4.9.1 Introduction to diagnostic information. .. . .46 4.9.2 GQL-status objects. .. . .46 4.9.3 Conditions.... 4.10 Procedures and commands.......... .49 4.10.1 General description of procedures and commands. . . . . . . .49 4.10.2 Procedures...... 49 4.10.2.1 General description of procedur