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: "a critique of ansi sql isolation levels"
  Abstract: ANSI SQL-92 defines Isolation Levels in terms of phenomena: Dirty Reads, Non-Repeatable Reads, and Phantoms. This paper shows that these phenomena and the ANSI SQL definitions fail to characterize several popular isolation levels, including the standard locking implementations of the levels. Investigating the ambiguities of the phenomena leads to clearer definitions; in addition new phenomena that better characterize isolation types are introduced. An important multiversion isolation type, Snapshot Isolation, is defined.

Connected through hyperedge HE-1 (induced by source paper "cloudburst stateful functions as a service"):
  with members:
    - "cloud programming simplified a berkeley view on serverless computing"
    - "serverless computing one step forward two steps back"
    - "pretzel opening the black box of machine learning prediction serving systems"
    - "numpywren serverless linear algebra"
    - "ray a distributed framework for emerging ai applications"
    - "occupy the cloud distributed computing for the 99"
    - "serverless computing current trends and open problems"
    - "mobilenets efficient convolutional neural networks for mobile vision applications"

Connected through hyperedge HE-2 (induced by source paper "analysis of indexing structures for immutable data"):
  with members:
    - "blockbench a framework for analyzing private blockchains"
    - "untangling blockchain a data processing view of blockchain systems"
    - "datahub collaborative data science dataset version management at scale"

Connected through hyperedge HE-3 (induced by source paper "analysis of indexing structures for immutable data full version"):
  with members:
    - "serializable snapshot isolation in postgresql"

Connected through hyperedge HE-4 (induced by source paper "hihooi a database replication middleware for scaling transactional databases consistently"):
  with members:
    - "middleware based database replication the gaps between theory and practice"

Connected through hyperedge HE-5 (induced by source paper "adapting persistent data structures for concurrency and speculation"):
  with members:
    - "distributionally linearizable data structures"
    - "pam parallel augmented maps"
    - "pragmatic primitives for non blocking data structures"
    - "techniques for constructing efficient lock free data structures"
    - "a general technique for non blocking trees"
    - "non determinism in byzantine fault tolerant replication"
    - "well structured futures and cache locality"
    - "flat combining and the synchronization parallelism tradeoff"

Connected through hyperedge HE-6 (induced by source paper "lockless transaction isolation in hyperledger fabric"):
  with members:
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "performance benchmarking and optimizing hyperledger fabric blockchain platform"
    - "blockchains consensus protocols in the wild"
    - "adding concurrency to smart contracts"
    - "serializable snapshot isolation in postgresql"

Connected through hyperedge HE-7 (induced by source paper "blockchain meets database design and implementation of a blockchain relational database"):
  with members:
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "xft practical fault tolerance beyond crashes"
    - "serializable snapshot isolation in postgresql"
    - "middleware based database replication the gaps between theory and practice"
    - "consensus on transaction commit"

Connected through hyperedge HE-8 (induced by source paper "distributed transactional systems cannot be fast"):
  with members:
    - "paris causally consistent transactions with non blocking reads and partial replication"
    - "distributed transactional reads the strong the quick the fresh the impossible"
    - "size aware sharding for improving tail latencies in in memory key value stores"
    - "causal consistency and latency optimality friend or foe"
    - "yesquel scalable sql storage for web applications"

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)