{
 "ticket": "U55 #92",
 "generatedAt": "2026-10-29T17:57:45.895525+08:00",
 "startedAt": "2026-10-29T17:57:45.658385+08:00",
 "exitCode": 0,
 "testCount": 8,
 "environment": {
  "os": "macOS-27.2-arm64-arm-64bit",
  "arch": "arm64",
  "serverVersion": "7.0.45",
  "maxWireVersion": 21,
  "mode": "standalone（DBngin 127.0.0.1:27017，用户实例；只创建并删除 u55_<run-id> 库）",
  "client": "Python 标准库 BSON + OP_MSG（无第三方驱动）"
 },
 "scope": "standalone",
 "database": "u55_d1098e7acf4f",
 "cleanupLeftover": [],
 "observations": [
  "U55 aggregationPushdown",
  "U55 changeStreamBoundary",
  "U55 cleanup",
  "U55 docSizeLimit",
  "U55 embeddedVsReferenced",
  "U55 indexPlan",
  "U55 schemaValidator",
  "U55 serverVersion",
  "U55 storageStats",
  "U55 transactionBoundary"
 ],
 "observed": [
  "U55 serverVersion=PASS version=7.0.45 maxWireVersion=21 replicaSet=False",
  "U55 docSizeLimit=PASS attemptedBytes=17825856 rejected=True code=10334 codeName=BSONObjectTooLarge limitBytes=16777216 semantics=server-enforced-document-boundary",
  "U55 embeddedVsReferenced=PASS embeddedHits=1 crossElementFlatHits=1 sameElementElemMatchHits=0 lookupJoined=1 joinedName=甲 semantics=dotpath-matches-across-elements-elemMatch-does-not",
  "U55 aggregationPushdown=PASS matchFirstExamined=100 matchFirstKeysExamined=100 matchFirstPlan=IXSCAN matchAfterGroupExamined=500 matchAfterGroupPlan=COLLSCAN earlyGroups=1 lateGroups=2 semantics=predicate-position-changes-plan",
  "U55 schemaValidator=PASS validInserted=True invalidWriteErrors=1 code=121 errorMessage='Document failed validation' semantics=validation-is-write-time-not-migration",
  "U55 indexPlan=PASS beforeIndexStage=COLLSCAN afterIndexStage=IXSCAN semantics=plan-change-not-just-speed",
  "U55 transactionBoundary=PASS replicaSet=False txnRejected=True code=20 insertedAnyway=0 message='Transaction numbers are only allowed on a replica set member' semantics=multi-document-transaction-requires-replica-set",
  "U55 changeStreamBoundary=PASS changeStreamRejected=True code=40573 replSetGetStatusRejected=True code=76 semantics=replica-set-features-unavailable-on-standalone",
  "U55 storageStats=PASS objects=505 dataSize=25313.0 storageSize=16384.0 indexSize=57344.0 ordersStorageSize=4096 ordersTotalIndexSize=24576 semantics=single-run-observation-not-baseline",
  "U55 cleanup=PASS dropped=True leftover=[]"
 ],
 "limits": [
  "复制集、分片、change stream 实际运行、事务提交与重试：未运行（本机只有 standalone），按票面“受阻仍算待验证”登记。",
  "容量数字为单次观察，非容量基线；未做数据增长与压缩对比。",
  "未安装 mongosh/pymongo；客户端为实验自带的最小 BSON+OP_MSG 实现，只覆盖本实验所需命令。"
 ]
}