{
  "schema_version": 1,
  "study_id": "postgresql-reference-2026-08-31",
  "measured_at_utc": "2026-08-31T23:15:50.9480418+05:00",
  "source_commit": "2b75d77b8fe0a529ae3e1fce120249b9acc921d8",
  "host": {
    "operating_system": "Microsoft Windows 11 Pro 10.0.22000 build 22000",
    "cpu": "Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GHz",
    "physical_cores": 14,
    "logical_processors": 28,
    "memory_bytes": 34278359040,
    "disk_model": "HS-SSD-WAVE(S) 512G",
    "disk_interface": "SCSI"
  },
  "software": {
    "postgresql": "psql (PostgreSQL) 18.3",
    "php": "8.5.7",
    "node": "v25.9.0",
    "application_server": "PHP built-in development server, eight independent workers",
    "operating_system_power_plan": "Power Scheme GUID: 381b4222-f694-41f0-9685-ff5bb260df2e  (Balanced)"
  },
  "database": {
    "shared_buffers": "128MB",
    "max_connections": 100,
    "connection_strategy": "PDO persistent connection scoped to each PHP worker; no external pooler",
    "database_size_bytes_after_runs": 86095551
  },
  "dataset": {
    "accounts": 100000,
    "events_after_runs": 504184,
    "initial_events": 500000,
    "generation": "Deterministic PostgreSQL generate_series statements in schema.sql"
  },
  "workload": {
    "warmup_seconds": 5,
    "measured_runs": 5,
    "seconds_per_run": 15,
    "concurrency": 32,
    "application_workers": 8,
    "request_mix": {
      "indexed_account_read_with_latest_event": "70%",
      "regional_grouped_aggregate": "20%",
      "transactional_update_and_event_insert": "10%"
    }
  },
  "observer": {
    "cpu": "Combined PostgreSQL and PHP process CPU time as a percentage of total host logical-processor capacity",
    "memory": "Combined PostgreSQL and PHP process working set",
    "io": "Windows per-process read/write transfer counters; includes cached and non-disk I/O",
    "connections": "pg_stat_activity count excluding the observer connection",
    "sampling_target_ms": 500
  },
  "source_tree": "The measured checkout included uncommitted benchmark harness changes; published source files and SHA-256 checksums are authoritative."
}