{"Entry":{"collection":"protocol","key":"logical-begin","name":"Begin (logical replication)","aliases":["Begin"],"metadata":{"aliases":["Begin"],"category":"Logical replication formats","content_hash":"a290f5e8d06c7c3fb892255df43d86eb48c7cdc34e7318965cebbe588f87689d","derived_content_hash":"815492e202ba3f3fa6117f474d8ba0cd6eed962431064adf82bf2fb676055cc5","imported_at":"2026-09-30T00:40:44.603465+08:00","name":"Begin (logical replication)","name_zh":"","slug":"logical-begin","summary":"Logical replication Begin format. Identifies the message as a begin message."}},"Definition":{"Collection":"protocol","Key":"logical-begin","SourceDatabase":"center","Version":"18","SourceTable":"protocol_message","SourceKey":"logical-begin","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"comparison_data":{"fields":[{"description":"Identifies the message as a begin message.","format":"Byte1('B')"},{"description":"The final LSN of the transaction.","format":"Int64 (XLogRecPtr)"},{"description":"Commit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01).","format":"Int64 (TimestampTz)"},{"description":"Xid of the transaction.","format":"Int32 (TransactionId)"}],"layer":"logical replication"},"comparison_hash":"04a178207058a2ffd62b8650c9c0611b7beef127f07f2edc67f25ae146fc6423","description":["Logical replication Begin format. Identifies the message as a begin message."],"description_zh":"Byte1('B') 将该消息标识为 Begin 消息。 Int64 (XLogRecPtr) 事务的最终 LSN。 Int64 (TimestampTz) 事务的提交时间戳。其值为自 PostgreSQL 纪元（2000-01-01）起经过的微秒数。 Int32 (TransactionId) 事务的 Xid。","description_zh_html":"\u003cp\u003e协议消息 Begin。\u003c/p\u003e\u003ch3\u003e同版本中文手册定义\u003c/h3\u003e\u003cdd\u003e\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('B')\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         将该消息标识为 Begin 消息。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt64 (XLogRecPtr)\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         事务的最终 LSN。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt64 (TimestampTz)\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         事务的提交时间戳。其值为自 PostgreSQL 纪元（2000-01-01）起经过的微秒数。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32 (TransactionId)\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         事务的 Xid。\n        \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e\u003c/dd\u003e\u003cp\u003e\u003ca href=\"/zh/docs/18/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-BEGIN\"\u003e查看完整中文手册与上下文\u003c/a\u003e。\u003c/p\u003e","facts":[{"label":"Layer","value":"Logical replication payload; distinct from the frontend/backend message envelope"},{"label":"First field","value":"Byte1('B')"}],"facts_zh":[{"label":"层次","value":"逻辑复制载荷，与前后端消息封装分开。"},{"label":"首个字段","value":"Byte1('B')"}],"fields":[{"description":"Identifies the message as a begin message.","format":"Byte1('B')"},{"description":"The final LSN of the transaction.","format":"Int64 (XLogRecPtr)"},{"description":"Commit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01).","format":"Int64 (TimestampTz)"},{"description":"Xid of the transaction.","format":"Int32 (TransactionId)"}],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('B')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a begin message.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt64 (XLogRecPtr)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe final LSN of the transaction.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt64 (TimestampTz)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eCommit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32 (TransactionId)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eXid of the transaction.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","manual_path":"/docs/18/protocol-logicalrep-message-formats.html","related":[{"label":"Streaming replication protocol","url":"/docs/18/protocol-replication.html"},{"label":"Logical Decoding Plugins","url":"/wiki/decode/?v=18"}],"release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[{"paragraphs":["This section describes the detailed format of each logical replication message. These messages are either returned by the replication slot SQL interface or are sent by a walsender. In the case of a walsender, they are encapsulated inside replication protocol WAL messages as described in Section 54.4 , and generally obey the same message flow as physical replication. The following messages (Stream Start, Stream Stop, Stream Commit, and Stream Abort) are available since protocol version 2. The following messages (Begin Prepare, Prepare, Commit Prepared, Rollback Prepared, Stream Prepare) are available since protocol version 3. The following message parts are shared by the above messages."],"title":"Protocol context"}],"sections_zh":[{"paragraphs":["本节说明各逻辑复制消息的详细格式。这些消息由复制槽 SQL 接口返回，或由 walsender 发送。由 walsender 发送时，它们被封装在复制协议的 WAL 消息中（参见第 54.4 节），消息流程通常与物理复制相同。Stream Start、Stream Stop、Stream Commit 和 Stream Abort 从协议版本 2 起可用。Begin Prepare、Prepare、Commit Prepared、Rollback Prepared 和 Stream Prepare 从协议版本 3 起可用。以下消息部分为上述消息所共用。"],"title":"协议上下文"}],"signature":"Begin","sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-logicalrep-message-formats.html","sha256":"e976b008206820fbeb1eba226e69bb7c00af157372c3545375d1b5053c76d0ad","url":"/docs/18/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-BEGIN"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('B')","c2":"Identifies the message as a begin message."},{"c0":"2","c1":"Int64 (XLogRecPtr)","c2":"The final LSN of the transaction."},{"c0":"3","c1":"Int64 (TimestampTz)","c2":"Commit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01)."},{"c0":"4","c1":"Int32 (TransactionId)","c2":"Xid of the transaction."}],"title":"Fields in documented order"}],"tables_zh":[{"columns":[{"key":"c0","label":"位置"},{"key":"c1","label":"格式"},{"key":"c2","label":"含义"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('B')","c2":"将该消息标识为 Begin 消息。"},{"c0":"2","c1":"Int64 (XLogRecPtr)","c2":"事务的最终 LSN。"},{"c0":"3","c1":"Int64 (TimestampTz)","c2":"事务的提交时间戳。其值为自 PostgreSQL 纪元（2000-01-01）起经过的微秒数。"},{"c0":"4","c1":"Int32 (TransactionId)","c2":"事务的 Xid。"}],"title":"按手册顺序排列的字段"}],"zh_from":{"authored_translation":"source-derived-identity","body_sha256":"36e24876b096ec804bea87d24525b6363b16b83338758d321608e62284506ff6","kind":"same-version-chinese-manual-with-source-derived-identity","manual":{"anchor":"PROTOCOL-LOGICALREP-MESSAGE-FORMATS-BEGIN","build_id":107,"extraction":"exact-definition","fragment_sha256":"9c9c789f3c9d0ff0f4231773e5c2e9450e8cea4094602799f2ba04cbe7064f63","locale":"zh-Hans","page_key":"protocol-logicalrep-message-formats.html","source_hash":"9561d3a39aca911a61b68b188aa97828e60fb6f7d81323d8aada08fe67259039","source_revision":"unknown:rendered-translation-baseline","translated_from_revision":null,"translation_revision":"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b","url":"/zh/docs/18/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-BEGIN","version":"18"},"runtime_rerun":false,"source_facts_revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}},"ManualEvidence":{"manual_path":"/docs/18/protocol-logicalrep-message-formats.html","release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-logicalrep-message-formats.html","sha256":"e976b008206820fbeb1eba226e69bb7c00af157372c3545375d1b5053c76d0ad","url":"/docs/18/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-BEGIN"}]},"MeasuredEvidence":{}},"Text":{"Collection":"protocol","Key":"logical-begin","SourceDatabase":"center","Version":"18","Locale":"en","Title":"Begin (logical replication)","Summary":"Logical replication Begin format. Identifies the message as a begin message.","BodyHTML":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eByte1(\u0026#39;B\u0026#39;)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a begin message.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt64 (XLogRecPtr)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe final LSN of the transaction.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt64 (TimestampTz)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eCommit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32 (TransactionId)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eXid of the transaction.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","ContentHash":"deec9d206647df3488fc913f70ff164a7580303ed0a11d0996dc2f60f27b867d","Payload":{"description":["Logical replication Begin format. Identifies the message as a begin message."],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('B')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a begin message.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt64 (XLogRecPtr)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe final LSN of the transaction.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt64 (TimestampTz)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eCommit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32 (TransactionId)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eXid of the transaction.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","related":[{"label":"Streaming replication protocol","url":"/docs/18/protocol-replication.html"},{"label":"Logical Decoding Plugins","url":"/wiki/decode/?v=18"}],"sections":[{"paragraphs":["This section describes the detailed format of each logical replication message. These messages are either returned by the replication slot SQL interface or are sent by a walsender. In the case of a walsender, they are encapsulated inside replication protocol WAL messages as described in Section 54.4 , and generally obey the same message flow as physical replication. The following messages (Stream Start, Stream Stop, Stream Commit, and Stream Abort) are available since protocol version 2. The following messages (Begin Prepare, Prepare, Commit Prepared, Rollback Prepared, Stream Prepare) are available since protocol version 3. The following message parts are shared by the above messages."],"title":"Protocol context"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('B')","c2":"Identifies the message as a begin message."},{"c0":"2","c1":"Int64 (XLogRecPtr)","c2":"The final LSN of the transaction."},{"c0":"3","c1":"Int64 (TimestampTz)","c2":"Commit timestamp of the transaction. The value is in number of microseconds since PostgreSQL epoch (2000-01-01)."},{"c0":"4","c1":"Int32 (TransactionId)","c2":"Xid of the transaction."}],"title":"Fields in documented order"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}