{"kind": "protocol", "major": "18", "item": {"slug": "logical-message", "name": "Message (logical replication)", "name_zh": "", "category": "Logical replication formats", "summary": "Logical replication Message format. Identifies the message as a logical decoding message.", "aliases": ["Message"], "content_hash": "e114c30bf2387ec527579106b85601dc78f7a1f4772442c48b9142cad12b34bc", "versions": {"14": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/14/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=14", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "label": "14.24", "major": "14", "channel": "stable", "revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "sources": [{"url": "/docs/14/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 14 English manual", "sha256": "4d5309e6070938fb53a3380c66fb64152d7984a368c86536d69ecac5bdb42852"}], "sections": [{"title": "Protocol context", "paragraphs": ["This section describes the detailed format of each logical replication message. These messages are returned either by the replication slot SQL interface or are sent by a walsender. In case of a walsender they are encapsulated inside the replication protocol WAL messages as described in Section 53.4 and generally obey 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 message parts are shared by the above messages."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/14/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "3829c23b52c6b6397d86290553349c1563e40275f8c0cc27fa5b499521105205"}, "15": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/15/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=15", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "label": "15.19", "major": "15", "channel": "stable", "revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "sources": [{"url": "/docs/15/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 15 English manual", "sha256": "dce726e09e3bfedfcea89e211772f1afb48a00fd03f33fb94ce66e6d6e2938f5"}], "sections": [{"title": "Protocol context", "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 55.4 , 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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/15/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}, "16": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/16/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=16", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "label": "16.15", "major": "16", "channel": "stable", "revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "sources": [{"url": "/docs/16/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 16 English manual", "sha256": "23e3687e7c97c6a17a24684c30716fb7beed99c85967e828f4ee378effb5b50e"}], "sections": [{"title": "Protocol context", "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 55.4 , 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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/16/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}, "17": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/17/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=17", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "label": "17.11", "major": "17", "channel": "stable", "revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "sources": [{"url": "/docs/17/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 17 English manual", "sha256": "438b6a09f48bd0e9d2424559a0ab950dce44a9ab6573d362362c1c8d0b375fe3"}], "sections": [{"title": "Protocol context", "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 53.4 , 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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/17/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}, "18": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/18/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=18", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "label": "18.6", "major": "18", "channel": "stable", "revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "sources": [{"url": "/docs/18/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 18 English manual", "sha256": "e976b008206820fbeb1eba226e69bb7c00af157372c3545375d1b5053c76d0ad"}], "sections": [{"title": "Protocol context", "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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/18/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}, "19": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/19/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=19", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "label": "19beta4", "major": "19", "channel": "preview", "revision": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}, "sources": [{"url": "/docs/19/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 19 English manual", "sha256": "e09479de1e9cef5a4abc9703d423b68677f7f7e0e44c1098a2d37144980fd461"}], "sections": [{"title": "Protocol context", "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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/19/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}, "20": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/devel/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=20", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "label": "20devel", "major": "20", "channel": "devel", "revision": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, "sources": [{"url": "/docs/devel/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 20 English manual", "sha256": "1c5d9d7ff344de5d066562bb12e9db460a51b7713932ca201856714fa9477238"}], "sections": [{"title": "Protocol context", "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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/devel/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}}}, "snapshot": {"facts": [{"label": "Layer", "value": "Logical replication payload; distinct from the frontend/backend message envelope"}, {"label": "First field", "value": "Byte1('M')"}], "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}], "tables": [{"key": "fields", "rows": [{"c0": "1", "c1": "Byte1('M')", "c2": "Identifies the message as a logical decoding message."}, {"c0": "2", "c1": "Int32 (TransactionId)", "c2": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"c0": "3", "c1": "Int8", "c2": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"c0": "4", "c1": "Int64 (XLogRecPtr)", "c2": "The LSN of the logical decoding message."}, {"c0": "5", "c1": "String", "c2": "The prefix of the logical decoding message."}, {"c0": "6", "c1": "Int32", "c2": "Length of the content."}, {"c0": "7", "c1": "Byte n", "c2": "The content of the logical decoding message."}], "title": "Fields in documented order", "columns": [{"key": "c0", "label": "Position"}, {"key": "c1", "label": "Format"}, {"key": "c2", "label": "Meaning"}]}], "related": [{"url": "/docs/18/protocol-replication.html", "label": "Streaming replication protocol"}, {"url": "/wiki/decode/?v=18", "label": "Logical Decoding Plugins"}], "release": {"ref": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "label": "18.6", "major": "18", "channel": "stable", "revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "sources": [{"url": "/docs/18/protocol-logicalrep-message-formats.html#PROTOCOL-LOGICALREP-MESSAGE-FORMATS-MESSAGE", "path": "protocol-logicalrep-message-formats.html", "label": "PostgreSQL 18 English manual", "sha256": "e976b008206820fbeb1eba226e69bb7c00af157372c3545375d1b5053c76d0ad"}], "sections": [{"title": "Protocol context", "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."]}], "signature": "Message", "description": ["Logical replication Message format. Identifies the message as a logical decoding message."], "manual_html": "<dl><dd>\n<div class=\"variablelist\">\n<dl class=\"variablelist\">\n<dt><span class=\"term\">Byte1('M')</span></dt>\n<dd>\n<p>Identifies the message as a logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32 (TransactionId)</span></dt>\n<dd>\n<p>Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.</p>\n</dd>\n<dt><span class=\"term\">Int8</span></dt>\n<dd>\n<p>Flags; Either 0 for no flags or 1 if the logical decoding message is transactional.</p>\n</dd>\n<dt><span class=\"term\">Int64 (XLogRecPtr)</span></dt>\n<dd>\n<p>The LSN of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">String</span></dt>\n<dd>\n<p>The prefix of the logical decoding message.</p>\n</dd>\n<dt><span class=\"term\">Int32</span></dt>\n<dd>\n<p>Length of the content.</p>\n</dd>\n<dt><span class=\"term\">Byte<em class=\"replaceable\"><code>n</code></em></span></dt>\n<dd>\n<p>The content of the logical decoding message.</p>\n</dd>\n</dl>\n</div>\n</dd></dl>", "manual_path": "/docs/18/protocol-logicalrep-message-formats.html", "comparison_data": {"layer": "logical replication", "fields": [{"format": "Byte1('M')", "description": "Identifies the message as a logical decoding message."}, {"format": "Int32 (TransactionId)", "description": "Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2."}, {"format": "Int8", "description": "Flags; Either 0 for no flags or 1 if the logical decoding message is transactional."}, {"format": "Int64 (XLogRecPtr)", "description": "The LSN of the logical decoding message."}, {"format": "String", "description": "The prefix of the logical decoding message."}, {"format": "Int32", "description": "Length of the content."}, {"format": "Byte n", "description": "The content of the logical decoding message."}]}, "comparison_hash": "e342b37109a65064e914f18c92934727892fb2c60c929fa2221ad41dfbb7dbb8"}, "comparison": {"left": "17", "right": "18", "status": "unchanged", "diff": ""}}