{"Entry":{"collection":"protocol","key":"logical-type","name":"Type (logical replication)","aliases":["Type"],"metadata":{"aliases":["Type"],"category":"Logical replication formats","content_hash":"dc176cc6e8807959a7473be2d8e82172529b83283ca4ef94888561845a4ed3f4","imported_at":"2026-09-30T00:40:44.67442+08:00","name":"Type (logical replication)","name_zh":"","slug":"logical-type","summary":"Logical replication Type format. Identifies the message as a type message."}},"Definition":{"Collection":"protocol","Key":"logical-type","SourceDatabase":"center","Version":"18","SourceTable":"protocol_message","SourceKey":"logical-type","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"comparison_data":{"fields":[{"description":"Identifies the message as a type message.","format":"Byte1('Y')"},{"description":"Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.","format":"Int32 (TransactionId)"},{"description":"OID of the data type.","format":"Int32 (Oid)"},{"description":"Namespace (empty string for pg_catalog ).","format":"String"},{"description":"Name of the data type.","format":"String"}],"layer":"logical replication"},"comparison_hash":"7db6b107620c293ebedb351f55c057df1e1de20b35cef26d218a0d4e48994551","description":["Logical replication Type format. Identifies the message as a type message."],"facts":[{"label":"Layer","value":"Logical replication payload; distinct from the frontend/backend message envelope"},{"label":"First field","value":"Byte1('Y')"}],"fields":[{"description":"Identifies the message as a type message.","format":"Byte1('Y')"},{"description":"Xid of the transaction (only present for streamed transactions). This field is available since protocol version 2.","format":"Int32 (TransactionId)"},{"description":"OID of the data type.","format":"Int32 (Oid)"},{"description":"Namespace (empty string for pg_catalog ).","format":"String"},{"description":"Name of the data type.","format":"String"}],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('Y')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a type message.\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 (only present for streamed transactions). This field is available since protocol version 2.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32 (Oid)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eOID of the data type.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNamespace (empty string for \u003ccode class=\"literal\"\u003epg_catalog\u003c/code\u003e).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eName of the data type.\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"}],"signature":"Type","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-TYPE"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('Y')","c2":"Identifies the message as a type 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":"Int32 (Oid)","c2":"OID of the data type."},{"c0":"4","c1":"String","c2":"Namespace (empty string for pg_catalog )."},{"c0":"5","c1":"String","c2":"Name of the data type."}],"title":"Fields in documented order"}]},"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-TYPE"}]},"MeasuredEvidence":{}},"Text":{"Collection":"protocol","Key":"logical-type","SourceDatabase":"center","Version":"18","Locale":"en","Title":"Type (logical replication)","Summary":"Logical replication Type format. Identifies the message as a type message.","BodyHTML":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eByte1(\u0026#39;Y\u0026#39;)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a type message.\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 (only present for streamed transactions). This field is available since protocol version 2.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32 (Oid)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eOID of the data type.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNamespace (empty string for \u003ccode\u003epg_catalog\u003c/code\u003e).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eName of the data type.\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":"ed405f167331c8cf509631b804e572fd60a73ba6331696095e57f29196fee2cd","Payload":{"description":["Logical replication Type format. Identifies the message as a type message."],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('Y')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a type message.\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 (only present for streamed transactions). This field is available since protocol version 2.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32 (Oid)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eOID of the data type.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNamespace (empty string for \u003ccode class=\"literal\"\u003epg_catalog\u003c/code\u003e).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eName of the data type.\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('Y')","c2":"Identifies the message as a type 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":"Int32 (Oid)","c2":"OID of the data type."},{"c0":"4","c1":"String","c2":"Namespace (empty string for pg_catalog )."},{"c0":"5","c1":"String","c2":"Name of the data type."}],"title":"Fields in documented order"}]}},"RequestedLocale":"zh-Hans","Fallback":true,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}