40001 — serialization_failure：序列化失败

并发事务无法串行化，需回滚后重试。

英文手册覆盖始于 PostgreSQL 8.1. 来源历史与运行验证各自保留独立版本边界。

当前阅读 PG 18·选择有来源记录的版本

8.1 8.2 8.3 8.4 9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19 20

aliases: 未知
class name: Transaction Rollback
condition name: serialization_failure
lang: en
sqlstate: 40001

版本定义 PG 18

速览 {#at-a-glance}

40001 是 PostgreSQL 类别 40 transaction_rollback 中的 serialization_failure 条件。它告诉客户端，事务观察到的顺序无法与并发事务组成可串行化顺序，因此 PostgreSQL 中止冲突事务，让客户端重新执行。

代表性案例启动两个 SERIALIZABLE 事务，让它们读取同一值。第一个事务更新并提交；旧快照事务随后收到 could not serialize access due to concurrent update，进入 INERROR，只有 ROLLBACK 后才回到 IDLE。新的可串行化事务读取已提交值，执行 registry 中固定的 SET value = 2 操作并提交最终结果；这证明的是事务边界，不是业务计算逻辑。

运行 40001-manual-boundary-final-20260909 在 PostgreSQL 18.6 和隔离的 PostgreSQL 10.21 上均通过。逐目标断言和结构化观察见公开证据 JSON。

含义与触发路径 {#meaning}

在 SERIALIZABLE 隔离级别下，PostgreSQL 跟踪谓词和元组冲突；如果事务结果依赖一个无法串行化的顺序，就会拒绝该事务。旧事务更新之前已读取、后来被并发事务更新的行，是其中一个具体路径。SQLSTATE 说明事务结果，不说明业务操作是否应该重试。

执行器的更新路径使用 ERRCODE_T_R_SERIALIZATION_FAILURE 和 could not serialize access due to concurrent update 源码报文。其他序列化冲突可能使用不同报文，恢复冲突也可能附带 detail，但仍表达事务回滚语义。应用日志应保存完整诊断以及事务的读写集合。

40001 与 23505 不同：用户主动请求的重复值不自动成为序列化失败，即使某些并发生成键的设计会产生应用认为可重试的唯一冲突。应根据操作语义和完整事务历史决定重试策略。

报文与诊断 {#messages}

下面的调度需要两个会话分别建立最初的快照。最后一段使用新的连接和新的可串行化快照，这是完整重试的必要部分。

CREATE TABLE serial_rows(id integer PRIMARY KEY, value integer NOT NULL);
INSERT INTO serial_rows VALUES (1, 0);

-- 在第一次提交前打开两个 SERIALIZABLE 快照。
BEGIN ISOLATION LEVEL SERIALIZABLE;
BEGIN ISOLATION LEVEL SERIALIZABLE;

-- first 会话读到 0；stale 会话也读到同一个 0。
SELECT value FROM serial_rows WHERE id = 1;
SELECT value FROM serial_rows WHERE id = 1;

-- first 会话写入 1 并提交；随后 stale 会话用旧快照写入。
UPDATE serial_rows SET value = 1 WHERE id = 1;
COMMIT;
UPDATE serial_rows SET value = 2 WHERE id = 1;
-- UPDATE 报告 40001，事务变为 INERROR。
ROLLBACK;

-- 新的重试事务：读取新值，重新执行操作并提交。
BEGIN ISOLATION LEVEL SERIALIZABLE;
SELECT value FROM serial_rows WHERE id = 1;
UPDATE serial_rows SET value = 2 WHERE id = 1;
COMMIT;
SELECT value FROM serial_rows WHERE id = 1;

PostgreSQL 18.6 返回：

SQLSTATE: 40001
severity: ERROR
message_primary: could not serialize access due to concurrent update
message_detail: <none>
source: nodeModifyTable.c / ExecUpdate / line 2604

PostgreSQL 10.21 的主报文相同，nodeModifyTable.c 行号随版本变化。本路径没有 message_detail；其他冲突来源可能附带更多字段。SQLSTATE 和事务已经中止的状态是稳定的重试信号。

诊断 {#diagnosis}

记录 SQLSTATE、严重级别、主报文、detail、hint、上下文、隔离级别、建立快照的语句以及事务状态。确认哪个事务先提交，以及哪些读取已过期。runner 断言两个初始读取都是 0，first 提交后为 IDLE，stale 事务在回滚前为 INERROR。

不要在失败事务上继续查询。先回滚，再以新的事务开始，并重复完整的读取、决策和写入。只重放最后一条 UPDATE 可能基于已经失效的快照作出决定。

处理与修复 {#response}

当操作为此设计时，应把 40001 当作事务重试信号：

回滚整个失败事务并释放锁。
按要求的隔离级别启动新事务，重新读取业务决策依赖的所有值。
使用有限退避和最大重试次数重新执行操作。
让操作具备幂等性，并在提交后验证最终业务结果。

代表性重试读取 1、写入 2、以 IDLE 状态提交，独立读取观察到最终值 2。这个隔离案例中的固定赋值不能证明生产环境任意计算都可重放；应用必须从新快照重新计算。

版本与边界 {#versions}

目录在 PostgreSQL 7.4 的锁定定义中已观察到 40001，并持续到 8.4.22 的 pre-9.0 定义；随后在列出的所有正式快照直到 PostgreSQL 18.6 以及 PostgreSQL 19 Beta 3 预览中存在。这是 definition_only 的存在边界，不是确切实现引入版本或运行时使用断言。9.0 到 9.1 之间记录了类别标题变化；目录保留该变化，扫描范围内条件没有其他定义变化。

旧快照更新案例在 PostgreSQL 18.6 和 10.21 上均通过。源码行号和冲突 detail 会因版本和冲突类型变化。本证据只覆盖旧快照更新及其新的完整重试，不声称所有 40001 路径使用相同报文，也不声称所有事务都能安全重试。

来源 {#sources}

结构化证据记录在公开证据 JSON中。源码记录固定到 PostgreSQL commit 724edf9bde9d356724ad384a2e196edc3c9f80f7；运行记录保留精确目标 ID 和结构化观察。

src.errcodes.18.6 — errcodes.txt
src.nodeModifyTable.18.6 — nodeModifyTable.c
doc.mvcc.18 — 序列化失败处理
Runtime：latest 与 pg10 均为 40001-manual-boundary-final-20260909，结构化观察见公开证据 JSON

比较版本

SQLSTATE 证据与已记录的运行版本

cases · serializable_stale_update

{
  "assertions": [
    "The stale writer receives 40001",
    "Its transaction is rolled back",
    "The first committed value remains before retry",
    "A fresh serializable snapshot is read, applied, and committed as a complete retry"
  ],
  "case_id": "serializable_stale_update",
  "cleanup": "Roll back workers and drop the case schema.",
  "has_snippet": true,
  "position": 0,
  "preconditions": [
    "Two sessions using SERIALIZABLE",
    "Both read the same row before either writes"
  ],
  "repair": "Retry the complete serializable transaction with bounded backoff and an idempotency policy; begin from a fresh snapshot and verify the final business result.",
  "trigger": "Commit one writer, then update the row from the stale serializable transaction.",
  "versions": [
    "10",
    "18"
  ]
}

claims · identity.class-and-condition

{
  "claim_id": "identity.class-and-condition",
  "limits": "Directory identity does not identify one serialization-conflict origin.",
  "method": "Read the Class 40 section and 40001 row in the frozen errcodes.txt snapshot.",
  "position": 0,
  "runtime": [],
  "sources": [
    "src.errcodes.18.6"
  ],
  "statement": "40001 is the serialization_failure condition in Class 40 transaction_rollback."
}

claims · mechanism.concurrent-update

{
  "claim_id": "mechanism.concurrent-update",
  "limits": "Other serialization conflicts can use different messages or source paths while retaining SQLSTATE 40001.",
  "method": "Trace the ExecUpdate concurrent-update branch and compare the diagnostic from the stale serializable writer.",
  "position": 1,
  "runtime": [],
  "sources": [
    "src.nodeModifyTable.18.6"
  ],
  "statement": "The executor update path reports ERRCODE_T_R_SERIALIZATION_FAILURE with could not serialize access due to concurrent update."
}

claims · runtime.fresh-snapshot-retry

{
  "claim_id": "runtime.fresh-snapshot-retry",
  "limits": "The fixed assignment is a controlled retry proof; it does not establish that an arbitrary business calculation is safe to replay. The run reads 1 and sets value=2; it does not test a business calculation decision.",
  "method": "Open both initial serializable snapshots before the first commit, trigger the stale update, roll it back, and assert the complete fresh read/fixed assignment/write retry and final value with registry transaction boundaries executed under autocommit=True.",
  "position": 2,
  "runtime": [],
  "sources": [
    "doc.mvcc.18",
    "case-manifest.40001",
    "runtime.40001-manual-boundary-final-20260909.latest",
    "runtime.40001-manual-boundary-final-20260909.pg10"
  ],
  "statement": "The stale serializable writer entered INERROR after 40001; after ROLLBACK, a fresh serializable transaction read 1, wrote 2, committed, and left final value 2 on both targets."
}

claims · versions.catalogue-boundary

{
  "claim_id": "versions.catalogue-boundary",
  "limits": "The first scanned release is a lower bound, not an asserted introduction version.",
  "method": "Read the manifest snapshots and definition references for the code.",
  "position": 3,
  "runtime": [],
  "sources": [
    "manifest.40001"
  ],
  "statement": "The locked catalogue records 40001 in every listed formal snapshot from 9.0.23 through 18.6 and in 19beta3; pre-9.0 history is not scanned."
}

messages · message.concurrent-update

{
  "limits": "The template is the observed executor update path; other serialization failures may carry different text or detail.",
  "message_id": "message.concurrent-update",
  "path": "",
  "position": 0,
  "raw": {
    "id": "message.concurrent-update",
    "limits": "The template is the observed executor update path; other serialization failures may carry different text or detail.",
    "primary_template": "could not serialize access due to concurrent update",
    "severity_source": "explicit ERROR",
    "sources": [
      "src.nodeModifyTable.18.6"
    ],
    "sqlstate": "40001"
  },
  "severity": "explicit ERROR",
  "sources": [
    "src.nodeModifyTable.18.6"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "could not serialize access due to concurrent update",
      "position": 0,
      "role": "",
      "template": "could not serialize access due to concurrent update"
    }
  ]
}

runtimes · runtime.40001-registry-final-20260909.latest · 18.6 (Homebrew) · passed

{
  "cases": [
    "serializable_stale_update"
  ],
  "limits": "",
  "position": 0,
  "raw": {
    "cases": [
      "serializable_stale_update"
    ],
    "id": "runtime.40001-registry-final-20260909.latest",
    "observed": {
      "diagnostic": {
        "message_primary": "could not serialize access due to concurrent update",
        "severity": "ERROR",
        "source_file": "nodeModifyTable.c",
        "source_function": "ExecUpdate",
        "source_line": "2604",
        "sqlstate": "40001"
      },
      "final_value": 2,
      "reads": {
        "first": 0,
        "retry": 1,
        "stale": 0
      },
      "statuses": {
        "first_after_commit": "IDLE",
        "retry": "IDLE",
        "stale_after_error": "INERROR",
        "stale_after_rollback": "IDLE"
      }
    },
    "raw": "verify/results/40001-registry-final-20260909/latest/raw.jsonl",
    "raw_sha256": "6a0f6ba16f654c5a3513a19647a5ef3a3e6908802133414d1a8ccd09de6a39ac",
    "run_id": "40001-registry-final-20260909",
    "server_version": "18.6 (Homebrew)",
    "server_version_num": 180006,
    "snippet_registry": {
      "path": "verify/cases/40001/snippets.json",
      "sha256": "7ed0b0bf4dc0bb2a2141a1cf9b223b61d80c9817ca041355d1f6527fbbb98007"
    },
    "status": "passed",
    "summary": "verify/results/40001-registry-final-20260909/latest/summary.json",
    "summary_sha256": "d4d8fdec585ef6fbe571940646d91cda6568befc64e12211ee17888a6c5b2433",
    "target": "latest"
  },
  "run_id": "40001-registry-final-20260909",
  "runtime_id": "runtime.40001-registry-final-20260909.latest",
  "server_version": "18.6 (Homebrew)",
  "status": "passed",
  "target": "latest"
}

runtimes · runtime.40001-registry-final-20260909.pg10 · 10.21 (Debian 10.21-1.pgdg90+1) · passed

{
  "cases": [
    "serializable_stale_update"
  ],
  "limits": "",
  "position": 1,
  "raw": {
    "cases": [
      "serializable_stale_update"
    ],
    "id": "runtime.40001-registry-final-20260909.pg10",
    "image": "postgres@sha256:b2baf8998630663d21370da06387c950e587071bdd307ee34e661cdcc7442bcc",
    "observed": {
      "diagnostic": {
        "message_primary": "could not serialize access due to concurrent update",
        "severity": "ERROR",
        "source_file": "nodeModifyTable.c",
        "source_function": "ExecUpdate",
        "source_line": "1012",
        "sqlstate": "40001"
      },
      "final_value": 2,
      "reads": {
        "first": 0,
        "retry": 1,
        "stale": 0
      },
      "statuses": {
        "first_after_commit": "IDLE",
        "retry": "IDLE",
        "stale_after_error": "INERROR",
        "stale_after_rollback": "IDLE"
      }
    },
    "raw": "verify/results/40001-registry-final-20260909/pg10/raw.jsonl",
    "raw_sha256": "85985ffb3f1599df3bc38d65651cb2a532b329e10ab2029481733b3e8a501867",
    "run_id": "40001-registry-final-20260909",
    "server_version": "10.21 (Debian 10.21-1.pgdg90+1)",
    "server_version_num": 100021,
    "snippet_registry": {
      "path": "verify/cases/40001/snippets.json",
      "sha256": "7ed0b0bf4dc0bb2a2141a1cf9b223b61d80c9817ca041355d1f6527fbbb98007"
    },
    "status": "passed",
    "summary": "verify/results/40001-registry-final-20260909/pg10/summary.json",
    "summary_sha256": "45e3f031aa5d5cb02adc714c3cbfcb27e9d166bf884c6d8405559a60b840ba45",
    "target": "pg10"
  },
  "run_id": "40001-registry-final-20260909",
  "runtime_id": "runtime.40001-registry-final-20260909.pg10",
  "server_version": "10.21 (Debian 10.21-1.pgdg90+1)",
  "status": "passed",
  "target": "pg10"
}

runtimes · runtime.40001-manual-boundary-final-20260909.latest · 18.6 (Homebrew) · passed

{
  "cases": [
    "serializable_stale_update"
  ],
  "limits": "",
  "position": 2,
  "raw": {
    "cases": [
      "serializable_stale_update"
    ],
    "id": "runtime.40001-manual-boundary-final-20260909.latest",
    "observed": {
      "connections_autocommit": {
        "first": true,
        "retry": true,
        "stale": true
      },
      "diagnostic": {
        "message_primary": "could not serialize access due to concurrent update",
        "severity": "ERROR",
        "source_file": "nodeModifyTable.c",
        "source_function": "ExecUpdate",
        "source_line": "2604",
        "sqlstate": "40001"
      },
      "final_value": 2,
      "reads": {
        "first": 0,
        "retry": 1,
        "stale": 0
      },
      "retry_semantics": "Fresh retry read 1, then fixed SET value=2; this case does not test a business calculation.",
      "statuses": {
        "first_after_commit": "IDLE",
        "retry": "IDLE",
        "stale_after_error": "INERROR",
        "stale_after_rollback": "IDLE"
      },
      "transaction_control": "Registry BEGIN/COMMIT/ROLLBACK statements run with autocommit=True; no driver implicit BEGIN participates."
    },
    "raw": "verify/results/40001-manual-boundary-final-20260909/latest/raw.jsonl",
    "raw_sha256": "befdfdf94a5577983557d64cecdd013f3e63c4e439388d1fc54e218937378b4f",
    "run_id": "40001-manual-boundary-final-20260909",
    "server_version": "18.6 (Homebrew)",
    "server_version_num": 180006,
    "snippet_registry": {
      "path": "verify/cases/40001/snippets.json",
      "sha256": "7ed0b0bf4dc0bb2a2141a1cf9b223b61d80c9817ca041355d1f6527fbbb98007"
    },
    "status": "passed",
    "summary": "verify/results/40001-manual-boundary-final-20260909/latest/summary.json",
    "summary_sha256": "6bbcb014add8ea24c8b6ba7663dade8b26a6ed6b2f95f544f9c8dc11a90cbcdf",
    "target": "latest"
  },
  "run_id": "40001-manual-boundary-final-20260909",
  "runtime_id": "runtime.40001-manual-boundary-final-20260909.latest",
  "server_version": "18.6 (Homebrew)",
  "status": "passed",
  "target": "latest"
}

runtimes · runtime.40001-manual-boundary-final-20260909.pg10 · 10.21 (Debian 10.21-1.pgdg90+1) · passed

{
  "cases": [
    "serializable_stale_update"
  ],
  "limits": "",
  "position": 3,
  "raw": {
    "cases": [
      "serializable_stale_update"
    ],
    "id": "runtime.40001-manual-boundary-final-20260909.pg10",
    "image": "postgres@sha256:b2baf8998630663d21370da06387c950e587071bdd307ee34e661cdcc7442bcc",
    "observed": {
      "connections_autocommit": {
        "first": true,
        "retry": true,
        "stale": true
      },
      "diagnostic": {
        "message_primary": "could not serialize access due to concurrent update",
        "severity": "ERROR",
        "source_file": "nodeModifyTable.c",
        "source_function": "ExecUpdate",
        "source_line": "1012",
        "sqlstate": "40001"
      },
      "final_value": 2,
      "reads": {
        "first": 0,
        "retry": 1,
        "stale": 0
      },
      "retry_semantics": "Fresh retry read 1, then fixed SET value=2; this case does not test a business calculation.",
      "statuses": {
        "first_after_commit": "IDLE",
        "retry": "IDLE",
        "stale_after_error": "INERROR",
        "stale_after_rollback": "IDLE"
      },
      "transaction_control": "Registry BEGIN/COMMIT/ROLLBACK statements run with autocommit=True; no driver implicit BEGIN participates."
    },
    "raw": "verify/results/40001-manual-boundary-final-20260909/pg10/raw.jsonl",
    "raw_sha256": "3d761eff0e571682ef5ea48bdd8ae8c355480f8775387e667c4db707f31d715f",
    "run_id": "40001-manual-boundary-final-20260909",
    "server_version": "10.21 (Debian 10.21-1.pgdg90+1)",
    "server_version_num": 100021,
    "snippet_registry": {
      "path": "verify/cases/40001/snippets.json",
      "sha256": "7ed0b0bf4dc0bb2a2141a1cf9b223b61d80c9817ca041355d1f6527fbbb98007"
    },
    "status": "passed",
    "summary": "verify/results/40001-manual-boundary-final-20260909/pg10/summary.json",
    "summary_sha256": "156c4129cf0b1b6a1108cf73353cca11425dbf353c4aa695261aeb7d8db1d992",
    "target": "pg10"
  },
  "run_id": "40001-manual-boundary-final-20260909",
  "runtime_id": "runtime.40001-manual-boundary-final-20260909.pg10",
  "server_version": "10.21 (Debian 10.21-1.pgdg90+1)",
  "status": "passed",
  "target": "pg10"
}

sources · src.errcodes.18.6

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "",
  "location": "lines 329-333",
  "path": "src/backend/utils/errcodes.txt",
  "position": 0,
  "sha256": "6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba",
  "source_id": "src.errcodes.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/errcodes.txt"
}

sources · src.nodeModifyTable.18.6

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "",
  "location": "lines 2595-2605",
  "path": "src/backend/executor/nodeModifyTable.c",
  "position": 1,
  "sha256": "0fc3cb180b3443f216142954e43d8ed5f84713d75094ce8cd2785ad8f604bd68",
  "source_id": "src.nodeModifyTable.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/executor/nodeModifyTable.c#L2595-L2605"
}

sources · doc.mvcc.18

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "",
  "location": "serialization failure handling",
  "path": "doc/src/sgml/mvcc.sgml",
  "position": 2,
  "sha256": "4b7bf77ee0af4b86052330ff2421d567df3604b75fe7d4f522bec84fdea87340",
  "source_id": "doc.mvcc.18",
  "tag": "PG18-docs",
  "url": "https://www.postgresql.org/docs/18/mvcc-serialization-failure-handling.html"
}

sources · doc.protocol.18

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "",
  "location": "ErrorResponse fields",
  "path": "doc/src/sgml/protocol.sgml",
  "position": 3,
  "sha256": "745339e07ebbc2bb67d98b258e25772ada644ef26011e3cd6b3fcbb435235f89",
  "source_id": "doc.protocol.18",
  "tag": "PG18-docs",
  "url": "https://www.postgresql.org/docs/18/protocol-error-fields.html"
}

sources · manifest.40001

{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "snapshots and definition_blobs entries for the 40001 definition",
  "path": "sources/manifest.lock.json",
  "position": 4,
  "sha256": "1727a275f336988ff96b4f9990a4ca253080f73fc5d316e7def165c8cf3708a8",
  "source_id": "manifest.40001",
  "tag": "",
  "url": "../sources/manifest.lock.json"
}

sources · case-manifest.40001

{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "serializable_stale_update",
  "path": "verify/cases/40001/cases.json",
  "position": 5,
  "sha256": "f763521e946921e560a2e2f769507be836cefae2ae2d0ca8d8d60a9c55c9e45b",
  "source_id": "case-manifest.40001",
  "tag": "",
  "url": "../verify/cases/40001/cases.json"
}

sources · snippet-registry.40001.final

{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "serializable_stale_update ordered SQL",
  "path": "verify/cases/40001/snippets.json",
  "position": 6,
  "sha256": "7ed0b0bf4dc0bb2a2141a1cf9b223b61d80c9817ca041355d1f6527fbbb98007",
  "source_id": "snippet-registry.40001.final",
  "tag": "",
  "url": "../verify/cases/40001/snippets.json"
}

来源引用

原始手册引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · english-manuals:7ba30bcee3df17e9903b7376a8990b2f57688e4496835e4011a2726294619699

正文语言: zh-Hans · english-manuals:7ba30bcee3df17e9903b7376a8990b2f57688e4496835e4011a2726294619699