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MySQL — How It Works

InnoDB storage engine, buffer pool, redo/undo logs, Group Replication, and HeatWave accelerator.

InnoDB Architecture

flowchart TB
    subgraph Server["MySQL Server Layer"]
        Parser["SQL Parser"]
        Optimizer["Query Optimizer"]
        Executor["Executor"]
    end

    subgraph InnoDB["InnoDB Storage Engine"]
        BP["Buffer Pool\n(page cache)"]
        CL["Change Buffer\n(secondary index updates)"]
        AHI["Adaptive Hash Index"]
        Redo["Redo Log\n(WAL for crash recovery)"]
        Undo["Undo Log\n(MVCC rollback)"]
        TS["Tablespaces\n(.ibd files)"]
    end

    Server --> InnoDB
    BP --> TS
    Redo --> TS

    style BP fill:#1565c0,color:#fff
    style Redo fill:#e65100,color:#fff

Group Replication

flowchart LR
    subgraph GR["Group Replication (Paxos)"]
        P["Primary\n(read-write)"]
        S1["Secondary 1\n(read-only)"]
        S2["Secondary 2\n(read-only)"]
    end

    P <-->|"Paxos consensus"| S1
    P <-->|"Paxos consensus"| S2
    S1 <-->|"Paxos consensus"| S2

    Client_M["Client"] --> P
    Client_M -.->|"read replicas"| S1
    Client_M -.->|"read replicas"| S2

    style P fill:#e65100,color:#fff

Sources