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: "high performance concurrency control mechanisms for main memory databases"
  Abstract: A database system optimized for in-memory storage can support much higher transaction rates than current systems. However, standard concurrency control methods used today do not scale to the high transaction rates achievable by such systems. In this paper we introduce two efficient concurrency control methods specifically designed for main-memory databases. Both use multiversioning to isolate read-only transactions from updates but differ in how atomicity is ensured: one is optimistic and one is pessimistic. To avoid expensive context switching, transactions never block during normal processing but they may have to wait before commit to ensure correct serialization ordering. We also implemented a main-memory optimized version of single-version locking. Experimental results show that while single-version locking works well when transactions are short and contention is low performance degrades under more demanding conditions. The multiversion schemes have higher overhead but are much less sensitive to hotspots and the presence of long-running transactions.

Connected through hyperedge HE-1 (induced by source paper "livegraph a transactional graph storage system with purely sequential adjacency list scans"):
  with members:
    - "tigergraph a native mpp graph database"
    - "in depth benchmarking of graph database systems with the linked data benchmark council ldbc social network benchmark snb"
    - "weaver a high performance transactional graph database based on refinable timestamps"
    - "graph analytics using the vertica relational database"
    - "rethinking serializable multiversion concurrency control"

Connected through hyperedge HE-2 (induced by source paper "nwr rethinking thomas write rule for omittable write operations"):
  with members:
    - "efficiently making almost any concurrency control mechanism serializable"
    - "serializable snapshot isolation in postgresql"
    - "a critique of ansi sql isolation levels"

Connected through hyperedge HE-3 (induced by source paper "gotcha an interactive debugger for got based distributed systems"):
  with members:
    - "got git but for objects"
    - "a graphical interactive debugger for distributed systems"
    - "on designing and testing distributed virtual environments"

Connected through hyperedge HE-4 (induced by source paper "scheduling oltp transactions via machine learning"):
  with members:
    - "improving high contention oltp performance via transaction scheduling"
    - "design principles for scaling multi core oltp under high contention"
    - "automatic partitioning of database applications"

Connected through hyperedge HE-5 (induced by source paper "star scaling transactions through asymmetric replication"):
  with members:
    - "obladi oblivious serializable transactions in the cloud"
    - "rethinking serializable multiversion concurrency control"

Connected through hyperedge HE-6 (induced by source paper "obladi oblivious serializable transactions in the cloud"):
  with members:
    - "spectre attacks exploiting speculative execution"
    - "atom horizontally scaling strong anonymity"
    - "safe serializable secure scheduling transactions and the trade off between security and consistency"

Connected through hyperedge HE-7 (induced by source paper "how to databasify a blockchain the case of hyperledger fabric"):
  with members:
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "untangling blockchain a data processing view of blockchain systems"

Connected through hyperedge HE-8 (induced by source paper "efficiently making almost any concurrency control mechanism serializable"):
  with members:
    - "rethinking serializable multiversion concurrency control"
    - "serializable snapshot isolation in postgresql"
    - "a critique of ansi sql isolation levels"

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)