{
  "schema_version": 1,
  "title": "Historical PostGamma state access comparison",
  "experiment_date": "2026-10-10",
  "comparison": "Two historical threaded server builds, before and after the change",
  "scope": "Read-only development experiment; not current release or cross-engine performance",
  "provenance": {
    "archive_name": "thread-state-access-20261010/evidence.tar.gz",
    "archive_sha256": "ecb27f7b3c9f928080fc4ccc949dbc2324b42b2f5359fe3233bf068bb75fc102",
    "summary_member": "diag-state/paired-a3/summary.json",
    "identity_member": "notes/final-identity.json",
    "patch_member": "notes/candidate-final.patch",
    "before_source_record": "d511f2b1fefa9a8a705f6940bc392aec23098baa",
    "after_source_head": "9e1461b2c94457cb8ed30ae599dcb30feeca734e"
  },
  "builds": {
    "before": {
      "binary_sha256": "9b144429799b57124f70056e39a36cf87d8efaf98176d5284b5ab6d901408971",
      "compiler_options": {
        "configure": "'--without-icu' '--disable-cassert' '--disable-debug' 'CC=gcc' 'CFLAGS=-O2 -g0' 'CPPFLAGS=-DEXEC_BACKEND' 'CXX=g++'",
        "cc": "gcc",
        "cflags": "-O2 -g0",
        "cppflags": "-DEXEC_BACKEND -D_GNU_SOURCE",
        "ldflags": "-Wl,--as-needed -Wl,-rpath,'/usr/local/pgsql/lib',--enable-new-dtags"
      }
    },
    "after": {
      "binary_sha256": "2ac68afa0e5b380d4512080f9aa76fba300d710856f1217ee17cb1c8af4a182c",
      "compiler_options": {
        "configure": "'--without-icu' '--disable-cassert' '--disable-debug' 'CC=gcc' 'CFLAGS=-O2 -g0' 'CPPFLAGS=-DEXEC_BACKEND' 'CXX=g++'",
        "cc": "gcc",
        "cflags": "-O2 -g0",
        "cppflags": "-DEXEC_BACKEND -D_GNU_SOURCE",
        "ldflags": "-Wl,--as-needed -Wl,-rpath,'/usr/local/pgsql/lib',--enable-new-dtags"
      }
    }
  },
  "method": {
    "pairs": 6,
    "operations_per_run": 100000,
    "run_order": "Alternating before/after order, after warmup",
    "timing": "Wall-clock timing without perf or ptrace instrumentation",
    "units": "Microseconds per completed operation",
    "reported_statistic": "Median across six runs per build",
    "storage": "tmpfs; read-only queries",
    "cpu_placement": "Same fixed backend CPU; separate client CPU",
    "cases": {
      "one": "SELECT 1 in a separate network request per operation",
      "point": "One prepared point query in a separate network request per operation",
      "batch": "Point queries inside one PL/pgSQL call; time per completed lookup"
    }
  },
  "limitations": [
    "The after build also includes a pointer initialization correctness fix.",
    "The timings do not isolate the causal effect of a single removed check.",
    "The network point-query case improved in only two of six pairs.",
    "The internal-loop case improved in five of six pairs, with one slower pair.",
    "Do not compare absolute loop timings with network request timings as identical work.",
    "The earlier native PostgreSQL control used different compiler flags and is omitted.",
    "These results do not establish disk-write, current package, or Wasm performance."
  ],
  "summary": {
    "status": "passed",
    "iterations": 6,
    "operations_per_trial": 100000,
    "cases": {
      "one": {
        "before": {
          "wall_us_median": 61.807719,
          "cpu_runtime_us_median": 43.039179704999995,
          "samples_wall_us": [
            63.748287,
            57.753676,
            68.479693,
            59.682988,
            63.439355,
            60.176083
          ]
        },
        "thread": {
          "wall_us_median": 61.7743855,
          "cpu_runtime_us_median": 42.26303154,
          "samples_wall_us": [
            60.92893,
            57.138806,
            64.919027,
            59.675013,
            62.910107,
            62.619841
          ]
        },
        "median_wall_change_percent": -0.05393096613062198,
        "paired_wall_change_percent": [
          -4.4226396232419525,
          -1.0646421883171442,
          -5.199593987665796,
          -0.013362266647909404,
          -0.8342581667168503,
          4.061012080164805
        ],
        "faster_pairs": 5
      },
      "point": {
        "before": {
          "wall_us_median": 78.925061,
          "cpu_runtime_us_median": 61.004733765,
          "samples_wall_us": [
            82.368989,
            78.542575,
            80.089541,
            78.126445,
            79.307547,
            71.737338
          ]
        },
        "thread": {
          "wall_us_median": 80.01794,
          "cpu_runtime_us_median": 61.664510379999996,
          "samples_wall_us": [
            76.405184,
            73.741617,
            88.197673,
            81.384923,
            81.139534,
            78.896346
          ]
        },
        "median_wall_change_percent": 1.3847046630727222,
        "paired_wall_change_percent": [
          -7.240352312688936,
          -6.1125548786756685,
          10.123833772502211,
          4.170774697351187,
          2.309978141172353,
          9.979472614386676
        ],
        "faster_pairs": 2
      },
      "batch": {
        "before": {
          "wall_us_median": 10.086611000000001,
          "cpu_runtime_us_median": 10.083365305000001,
          "samples_wall_us": [
            10.21258,
            9.067355,
            9.955645,
            11.449166,
            10.478739,
            9.960642
          ]
        },
        "thread": {
          "wall_us_median": 9.205476,
          "cpu_runtime_us_median": 9.202549755,
          "samples_wall_us": [
            9.431062,
            8.97989,
            12.154864,
            10.566928,
            8.806624,
            8.712063
          ]
        },
        "median_wall_change_percent": -8.735689321219986,
        "paired_wall_change_percent": [
          -7.652503089327089,
          -0.9646142673359503,
          22.0901709532632,
          -7.705696642008675,
          -15.957215844387385,
          -12.535125747918652
        ],
        "faster_pairs": 5
      }
    }
  }
}