{"Entry":{"collection":"protocol","key":"functioncall-f","name":"FunctionCall","aliases":["FunctionCall","Byte1('F')"],"metadata":{"aliases":["FunctionCall","Byte1('F')"],"category":"Frontend messages","content_hash":"d6d69a1b8cdf691921d7ea7633df34e042c15ff4b5c247e6ea73112376d83574","imported_at":"2026-09-30T00:40:44.550657+08:00","name":"FunctionCall","name_zh":"","slug":"functioncall-f","summary":"FunctionCall is a frontend protocol message. Identifies the message as a function call."}},"Definition":{"Collection":"protocol","Key":"functioncall-f","SourceDatabase":"center","Version":"18","SourceTable":"protocol_message","SourceKey":"functioncall-f","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"comparison_data":{"direction":"F","fields":[{"description":"Identifies the message as a function call.","format":"Byte1('F')"},{"description":"Length of message contents in bytes, including self.","format":"Int32"},{"description":"Specifies the object ID of the function to call.","format":"Int32"},{"description":"The number of argument format codes that follow (denoted C below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments.","format":"Int16"},{"description":"The argument format codes. 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Identifies the message as a function call."],"direction":"F","facts":[{"label":"Direction","value":"Frontend → backend"},{"label":"First wire field","value":"Byte1('F')"},{"label":"Field entries","value":"9"},{"label":"Documented flow contexts","value":"Function Call"}],"fields":[{"description":"Identifies the message as a function call.","format":"Byte1('F')"},{"description":"Length of message contents in bytes, including self.","format":"Int32"},{"description":"Specifies the object ID of the function to call.","format":"Int32"},{"description":"The number of argument format codes that follow (denoted C below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments.","format":"Int16"},{"description":"The argument format codes. Each must presently be zero (text) or one (binary).","format":"Int16[ C ]"},{"description":"Specifies the number of arguments being supplied to the function.","format":"Int16"},{"description":"The length of the argument value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case.","format":"Int32"},{"description":"The value of the argument, in the format indicated by the associated format code. n is the above length.","format":"Byte n"},{"description":"The format code for the function result. Must presently be zero (text) or one (binary).","format":"Int16"}],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('F')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a function call.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the object ID of the function to call.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe number of argument format codes that follow (denoted \u003cem class=\"replaceable\"\u003e\u003ccode\u003eC\u003c/code\u003e\u003c/em\u003e below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16[\u003cem class=\"replaceable\"\u003e\u003ccode\u003eC\u003c/code\u003e\u003c/em\u003e]\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe argument format codes. Each must presently be zero (text) or one (binary).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the number of arguments being supplied to the function.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eNext, the following pair of fields appear for each argument:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe length of the argument value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte\u003cem class=\"replaceable\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe value of the argument, in the format indicated by the associated format code. \u003cem class=\"replaceable\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is the above length.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eAfter the last argument, the following field appears:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe format code for the function result. Must presently be zero (text) or one (binary).\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-message-formats.html","related":[{"label":"Protocol flow and exchange examples","url":"/docs/18/protocol-flow.html"},{"label":"Protocol overview","url":"/docs/18/protocol-overview.html"},{"label":"Function Call","url":"/docs/18/protocol-flow.html#PROTOCOL-FLOW-FUNCTION-CALL"}],"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":["The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter."],"title":"Framing and repetition"}],"signature":"FunctionCall (F)","sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-message-formats.html","sha256":"53f37652ac2c089e30ada87d8aee7bdd0f26695b03f275302e526a807d2a1f23","url":"/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-FUNCTIONCALL"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('F')","c2":"Identifies the message as a function call."},{"c0":"2","c1":"Int32","c2":"Length of message contents in bytes, including self."},{"c0":"3","c1":"Int32","c2":"Specifies the object ID of the function to call."},{"c0":"4","c1":"Int16","c2":"The number of argument format codes that follow (denoted C below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments."},{"c0":"5","c1":"Int16[ C ]","c2":"The argument format codes. Each must presently be zero (text) or one (binary)."},{"c0":"6","c1":"Int16","c2":"Specifies the number of arguments being supplied to the function."},{"c0":"7","c1":"Int32","c2":"The length of the argument value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case."},{"c0":"8","c1":"Byte n","c2":"The value of the argument, in the format indicated by the associated format code. n is the above length."},{"c0":"9","c1":"Int16","c2":"The format code for the function result. Must presently be zero (text) or one (binary)."}],"title":"Wire fields in documented order"}]},"ManualEvidence":{"manual_path":"/docs/18/protocol-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-message-formats.html","sha256":"53f37652ac2c089e30ada87d8aee7bdd0f26695b03f275302e526a807d2a1f23","url":"/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-FUNCTIONCALL"}]},"MeasuredEvidence":{}},"Text":{"Collection":"protocol","Key":"functioncall-f","SourceDatabase":"center","Version":"18","Locale":"en","Title":"FunctionCall","Summary":"FunctionCall is a frontend protocol message. Identifies the message as a function call.","BodyHTML":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eByte1(\u0026#39;F\u0026#39;)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a function call.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the object ID of the function to call.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe number of argument format codes that follow (denoted \u003cem\u003e\u003ccode\u003eC\u003c/code\u003e\u003c/em\u003e below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt16[\u003cem\u003e\u003ccode\u003eC\u003c/code\u003e\u003c/em\u003e]\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe argument format codes. Each must presently be zero (text) or one (binary).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the number of arguments being supplied to the function.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eNext, the following pair of fields appear for each argument:\u003c/p\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe length of the argument value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eByte\u003cem\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe value of the argument, in the format indicated by the associated format code. \u003cem\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is the above length.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eAfter the last argument, the following field appears:\u003c/p\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe format code for the function result. Must presently be zero (text) or one (binary).\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":"3bc70d866a15eaa1dba09fd42e9b65ff2c9aac740a2597c84a72aa8b7bc83eb6","Payload":{"description":["FunctionCall is a frontend protocol message. Identifies the message as a function call."],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('F')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a function call.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the object ID of the function to call.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe number of argument format codes that follow (denoted \u003cem class=\"replaceable\"\u003e\u003ccode\u003eC\u003c/code\u003e\u003c/em\u003e below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16[\u003cem class=\"replaceable\"\u003e\u003ccode\u003eC\u003c/code\u003e\u003c/em\u003e]\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe argument format codes. Each must presently be zero (text) or one (binary).\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the number of arguments being supplied to the function.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eNext, the following pair of fields appear for each argument:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe length of the argument value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte\u003cem class=\"replaceable\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe value of the argument, in the format indicated by the associated format code. \u003cem class=\"replaceable\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is the above length.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eAfter the last argument, the following field appears:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe format code for the function result. Must presently be zero (text) or one (binary).\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","related":[{"label":"Protocol flow and exchange examples","url":"/docs/18/protocol-flow.html"},{"label":"Protocol overview","url":"/docs/18/protocol-overview.html"},{"label":"Function Call","url":"/docs/18/protocol-flow.html#PROTOCOL-FLOW-FUNCTION-CALL"}],"sections":[{"paragraphs":["The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter."],"title":"Framing and repetition"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('F')","c2":"Identifies the message as a function call."},{"c0":"2","c1":"Int32","c2":"Length of message contents in bytes, including self."},{"c0":"3","c1":"Int32","c2":"Specifies the object ID of the function to call."},{"c0":"4","c1":"Int16","c2":"The number of argument format codes that follow (denoted C below). This can be zero to indicate that there are no arguments or that the arguments all use the default format (text); or one, in which case the specified format code is applied to all arguments; or it can equal the actual number of arguments."},{"c0":"5","c1":"Int16[ C ]","c2":"The argument format codes. Each must presently be zero (text) or one (binary)."},{"c0":"6","c1":"Int16","c2":"Specifies the number of arguments being supplied to the function."},{"c0":"7","c1":"Int32","c2":"The length of the argument value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case."},{"c0":"8","c1":"Byte n","c2":"The value of the argument, in the format indicated by the associated format code. n is the above length."},{"c0":"9","c1":"Int16","c2":"The format code for the function result. Must presently be zero (text) or one (binary)."}],"title":"Wire 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}