human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "the sql query language configurable unifying and semi structured"
  Abstract: NoSQL databases support semi-structured data, typically modeled as JSON. They also provide limited (but expanding) query languages. Their idiomatic, non-SQL language constructs, the many variations, and the lack of formal semantics inhibit deep understanding of the query languages, and also impede progress towards clean, powerful, declarative query languages. #R##N#This paper specifies the syntax and semantics of SQL++, which is applicable to both JSON native stores and SQL databases. The SQL++ semi-structured data model is a superset of both JSON and the SQL data model. SQL++ offers powerful computational capabilities for processing semi-structured data akin to prior non-relational query languages, notably OQL and XQuery. Yet, SQL++ is SQL backwards compatible and is generalized towards JSON by introducing only a small number of query language extensions to SQL. #R##N#Recognizing that a query language standard is probably premature for the fast evolving area of NoSQL databases, SQL++ includes configuration options that formally itemize the semantics variations that language designers may choose from. The options often pertain to the treatment of semi-structuredness (missing attributes, heterogeneous types, etc), where more than one sensible approaches are possible. #R##N#SQL++ is unifying: By appropriate choices of configuration options, the SQL++ semantics can morph into the semantics of existing semi-structured database query languages. The extensive experimental validation shows how SQL and four semi-structured database query languages (MongoDB, Cassandra CQL, Couchbase N1QL and AsterixDB AQL) are formally described by appropriate settings of the configuration options. #R##N#Early adoption signs of SQL++ are positive: Version 4 of Couchbase's N1QL is explained as syntactic sugar over SQL++. AsterixDB will soon support the full SQL++ and Apache Drill is in the process of aligning with SQL++.

Connected through hyperedge HE-1 (induced by source paper "an lsm based tuple compaction framework for apache asterixdb"):
  with members:
    - "lsm based storage techniques a survey"
    - "efficient data ingestion and query processing for lsm based storage systems"
    - "asterixdb a scalable open source bdms"

Connected through hyperedge HE-2 (induced by source paper "an idea an ingestion framework for data enrichment in asterixdb"):
  with members:
    - "asterixdb a scalable open source bdms"

Connected through hyperedge HE-3 (induced by source paper "a tensor based data model for polystore an application to social networks data"):
  with members:
    - "laradb a minimalist kernel for linear and relational algebra computation"
    - "polystore mathematics of relational algebra"
    - "the bigdawg polystore system and architecture"
    - "measuring user influence on twitter"
    - "d4m bringing associative arrays to database engines"
    - "achieving 100 000 000 database inserts per second using accumulo and d4m"
    - "predicting successful memes using network and community structure"
    - "exposing multi relational networks to single relational network analysis algorithms"

Connected through hyperedge HE-4 (induced by source paper "modelwizard toward interactive model construction"):
  with members:
    - "associative arrays unified mathematics for spreadsheets databases matrices and graphs"
    - "empirical analysis of predictive algorithms for collaborative filtering"
    - "probabilistic programming concepts"
    - "compiling relational database schemata into probabilistic graphical models"
    - "operations for learning with graphical models"

Connected through hyperedge HE-5 (induced by source paper "a formal presentation of mongodb extended version"):
  with members:
    - "static and dynamic semantics of nosql languages"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.DB(Databases)