{"Entry":{"collection":"conn","key":"gssencmode","name":"gssencmode","aliases":["PGGSSENCMODE","gssencmode"],"metadata":{"aliases":["PGGSSENCMODE","gssencmode"],"category":"GSSAPI and Kerberos","content_hash":"1e924f04d3d8f9efb5fc8868052a3b722bc4953944d63704f5b6c82ada925483","imported_at":"2026-09-30T00:40:34.880016+08:00","name":"gssencmode","name_zh":"","slug":"gssencmode","summary":"This option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:"}},"Definition":{"Collection":"conn","Key":"gssencmode","SourceDatabase":"center","Version":"18","SourceTable":"connection_parameter","SourceKey":"gssencmode","SourceRevision":"ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8","Facts":{"comparison_data":{"compiled_default_expression":"DefaultGSSMode","default_evidence":["if there are GSSAPI credentials present (i.e., in a credentials cache), first try a GSSAPI -encrypted connection; if that fails or there are no credentials, try a non- GSSAPI -encrypted connection. This is the default when PostgreSQL has been compiled with GSSAPI support."],"definition":"This option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes: disable only try a non- GSSAPI -encrypted connection prefer (default) if there are GSSAPI credentials present (i.e., in a credentials cache), first try a GSSAPI -encrypted connection; if that fails or there are no credentials, try a non- GSSAPI -encrypted connection. This is the default when PostgreSQL has been compiled with GSSAPI support. require only try a GSSAPI -encrypted connection gssencmode is ignored for Unix domain socket communication. If PostgreSQL is compiled without GSSAPI support, using the require option will cause an error, while prefer will be accepted but libpq will not actually attempt a GSSAPI -encrypted connection.","documented":true,"environment":"PGGSSENCMODE","keyword":"gssencmode"},"comparison_hash":"402998f186138ef492d8315637bdecb8dd4b0e73f825d124c736b6a496a1cc09","default_evidence":["if there are GSSAPI credentials present (i.e., in a credentials cache), first try a GSSAPI -encrypted connection; if that fails or there are no credentials, try a non- GSSAPI -encrypted connection. This is the default when PostgreSQL has been compiled with GSSAPI support."],"description":["This option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:"],"documented":true,"environment":[{"description":"PGGSSENCMODE behaves the same as the gssencmode connection parameter.","name":"PGGSSENCMODE","source_url":"/docs/18/libpq-envars.html"}],"facts":[{"label":"Client library","value":"libpq 18.6"},{"label":"Manual definition","value":"Documented"},{"label":"Source environment fallback","value":"PGGSSENCMODE"},{"label":"Compiled fallback expression","value":"DefaultGSSMode"}],"keyword":"gssencmode","manual_html":"\u003cdiv\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt id=\"LIBPQ-CONNECT-GSSENCMODE\"\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003egssencmode\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\n\u003cp\u003eThis option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003edisable\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eonly try a non-GSSAPI-encrypted connection\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eprefer\u003c/code\u003e (default)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eif there are GSSAPI credentials present (i.e., in a credentials cache), first try a GSSAPI-encrypted connection; if that fails or there are no credentials, try a non-GSSAPI-encrypted connection. This is the default when \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e has been compiled with GSSAPI support.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003erequire\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eonly try a GSSAPI-encrypted connection\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003ccode class=\"literal\"\u003egssencmode\u003c/code\u003e is ignored for Unix domain socket communication. If \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e is compiled without GSSAPI support, using the \u003ccode class=\"literal\"\u003erequire\u003c/code\u003e option will cause an error, while \u003ccode class=\"literal\"\u003eprefer\u003c/code\u003e will be accepted but \u003cspan class=\"application\"\u003elibpq\u003c/span\u003e will not actually attempt a GSSAPI-encrypted connection.\u003c/p\u003e\n\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","manual_path":"libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE","precedence_evidence":["The following environment variables can be used to select default connection parameter values, which will be used by PQconnectdb , PQsetdbLogin and PQsetdb if no value is directly specified by the calling code. These are useful to avoid hard-coding database connection information into simple client applications, for example.","Service names can be defined in either a per-user service file or a system-wide file. If the same service name exists in both the user and the system file, the user file takes precedence. By default, the per-user service file is named ~/.pg_service.conf . On Microsoft Windows, it is named %APPDATA%\\postgresql\\.pg_service.conf (where %APPDATA% refers to the Application Data subdirectory in the user's profile). A different file name can be specified by setting the environment variable PGSERVICEFILE . The system-wide file is named pg_service.conf . By default it is sought in the etc directory of the PostgreSQL installation (use pg_config --sysconfdir to identify this directory precisely). Another directory, but not a different file name, can be specified by setting the environment variable PGSYSCONFDIR .","Connection parameters obtained from a service file are combined with parameters obtained from other sources. A service file setting overrides the corresponding environment variable, and in turn can be overridden by a value given directly in the connection string. For example, using the above service file, a connection string service=mydb port=5434 will use host somehost , port 5434 , user admin , and other parameters as set by environment variables or built-in defaults."],"related":[{"label":"Connection service file","url":"/docs/18/libpq-pgservice.html"},{"label":"Password file","url":"/docs/18/libpq-pgpass.html"},{"label":"All libpq environment variables","url":"/docs/18/libpq-envars.html"}],"release":{"channel":"stable","evidence_kind":"English manual and source declarations","label":"18.6","major":"18","manifest":{"index":"index.html","major":"18","pages":1148,"pdf":{"A4":{"built_at":"2026-09-26","bytes":15865106,"pages":3154,"sha256":"19512c405da53f9f7fcf0abba359223aa65f021be025bf3411381918f92e3190","url":"/files/documentation/pdf/18/postgresql-18-A4.pdf"},"US":{"built_at":"2026-09-26","bytes":15748059,"pages":3328,"sha256":"facbe6c229e598b872d3d98bef53308f46e06746006fa4590de9a7de9dd46319","url":"/files/documentation/pdf/18/postgresql-18-US.pdf"}},"release":"18.6","source_mode":"en SGML built with pinned official archive","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","source_url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","svg_assets":3,"tree":"18"},"ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[{"paragraphs":["The following environment variables can be used to select default connection parameter values, which will be used by PQconnectdb , PQsetdbLogin and PQsetdb if no value is directly specified by the calling code. These are useful to avoid hard-coding database connection information into simple client applications, for example.","Service names can be defined in either a per-user service file or a system-wide file. If the same service name exists in both the user and the system file, the user file takes precedence. By default, the per-user service file is named ~/.pg_service.conf . On Microsoft Windows, it is named %APPDATA%\\postgresql\\.pg_service.conf (where %APPDATA% refers to the Application Data subdirectory in the user's profile). A different file name can be specified by setting the environment variable PGSERVICEFILE . The system-wide file is named pg_service.conf . By default it is sought in the etc directory of the PostgreSQL installation (use pg_config --sysconfdir to identify this directory precisely). Another directory, but not a different file name, can be specified by setting the environment variable PGSYSCONFDIR .","Connection parameters obtained from a service file are combined with parameters obtained from other sources. A service file setting overrides the corresponding environment variable, and in turn can be overridden by a value given directly in the connection string. For example, using the above service file, a connection string service=mydb port=5434 will use host somehost , port 5434 , user admin , and other parameters as set by environment variables or built-in defaults."],"title":"Default resolution and service-file precedence"},{"paragraphs":["PGGSSENCMODE behaves the same as the gssencmode connection parameter."],"title":"Environment variable evidence"}],"signature":"gssencmode","source_option":{"compiled_default_expression":"DefaultGSSMode","declaration":"\"gssencmode\", \"PGGSSENCMODE\", DefaultGSSMode, NULL, \"GSSENC-Mode\", \"\", 8, offsetof(struct pg_conn, gssencmode)","environment":"PGGSSENCMODE","keyword":"gssencmode","source_notes":[]},"sources":[{"anchor":"LIBPQ-CONNECT-GSSENCMODE","file":"libpq-connect.html","label":"18.6 English manual · libpq-connect.html","sha256":"c26a7fc3dcda6066cfe540641ae2690faf3d3c03277f30b4dfc2328ab45c212f","url":"/docs/18/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE"},{"archive_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","file":"src/interfaces/libpq/fe-connect.c","label":"18.6 libpq connection option declarations","sha256":"44a6e386cbfd67ebe768d6ef5493098119c2e6b4796239d53e5ed7b122b206a5","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"anchor":"","file":"libpq-envars.html","label":"18.6 English manual · libpq-envars.html","sha256":"d64db73f3d48127bb984a5f775e77b7bcca2ba4bd218333cf24a45fcdd7c4363","url":"/docs/18/libpq-envars.html"},{"anchor":"","file":"libpq-pgservice.html","label":"18.6 English manual · libpq-pgservice.html","sha256":"6035a3f0ee1d0fd80db5bf58834390b884eecd23206659bdf6f07560deea5aa7","url":"/docs/18/libpq-pgservice.html"}],"tables":[{"columns":[{"key":"name","label":"Variable"},{"key":"description","label":"Documented behavior"}],"key":"environment","rows":[{"description":"PGGSSENCMODE behaves the same as the gssencmode connection parameter.","name":{"text":"PGGSSENCMODE","url":"/docs/18/libpq-envars.html"}}],"title":"Environment fallback"}]},"ManualEvidence":{"manual_path":"libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE","release":{"channel":"stable","evidence_kind":"English manual and source declarations","label":"18.6","major":"18","manifest":{"index":"index.html","major":"18","pages":1148,"pdf":{"A4":{"built_at":"2026-09-26","bytes":15865106,"pages":3154,"sha256":"19512c405da53f9f7fcf0abba359223aa65f021be025bf3411381918f92e3190","url":"/files/documentation/pdf/18/postgresql-18-A4.pdf"},"US":{"built_at":"2026-09-26","bytes":15748059,"pages":3328,"sha256":"facbe6c229e598b872d3d98bef53308f46e06746006fa4590de9a7de9dd46319","url":"/files/documentation/pdf/18/postgresql-18-US.pdf"}},"release":"18.6","source_mode":"en SGML built with pinned official archive","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","source_url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","svg_assets":3,"tree":"18"},"ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sources":[{"anchor":"LIBPQ-CONNECT-GSSENCMODE","file":"libpq-connect.html","label":"18.6 English manual · libpq-connect.html","sha256":"c26a7fc3dcda6066cfe540641ae2690faf3d3c03277f30b4dfc2328ab45c212f","url":"/docs/18/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE"},{"archive_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","file":"src/interfaces/libpq/fe-connect.c","label":"18.6 libpq connection option declarations","sha256":"44a6e386cbfd67ebe768d6ef5493098119c2e6b4796239d53e5ed7b122b206a5","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"anchor":"","file":"libpq-envars.html","label":"18.6 English manual · libpq-envars.html","sha256":"d64db73f3d48127bb984a5f775e77b7bcca2ba4bd218333cf24a45fcdd7c4363","url":"/docs/18/libpq-envars.html"},{"anchor":"","file":"libpq-pgservice.html","label":"18.6 English manual · libpq-pgservice.html","sha256":"6035a3f0ee1d0fd80db5bf58834390b884eecd23206659bdf6f07560deea5aa7","url":"/docs/18/libpq-pgservice.html"}]},"MeasuredEvidence":{}},"Text":{"Collection":"conn","Key":"gssencmode","SourceDatabase":"center","Version":"18","Locale":"en","Title":"gssencmode","Summary":"This option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:","BodyHTML":"\u003cdiv\u003e\u003cdl\u003e\u003cdt id=\"LIBPQ-CONNECT-GSSENCMODE\"\u003e\u003cspan\u003e\u003ccode\u003egssencmode\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\n\u003cp\u003eThis option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:\u003c/p\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003e\u003ccode\u003edisable\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eonly try a non-GSSAPI-encrypted connection\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003e\u003ccode\u003eprefer\u003c/code\u003e (default)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eif there are GSSAPI credentials present (i.e., in a credentials cache), first try a GSSAPI-encrypted connection; if that fails or there are no credentials, try a non-GSSAPI-encrypted connection. This is the default when \u003cspan\u003ePostgreSQL\u003c/span\u003e has been compiled with GSSAPI support.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003e\u003ccode\u003erequire\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eonly try a GSSAPI-encrypted connection\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003ccode\u003egssencmode\u003c/code\u003e is ignored for Unix domain socket communication. If \u003cspan\u003ePostgreSQL\u003c/span\u003e is compiled without GSSAPI support, using the \u003ccode\u003erequire\u003c/code\u003e option will cause an error, while \u003ccode\u003eprefer\u003c/code\u003e will be accepted but \u003cspan\u003elibpq\u003c/span\u003e will not actually attempt a GSSAPI-encrypted connection.\u003c/p\u003e\n\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","SourceRevision":"ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8","ContentHash":"662f6befe11ebf12825fdf48308681ff3828f4226306d436f5a4c00eb20e1e6f","Payload":{"description":["This option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:"],"manual_html":"\u003cdiv\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt id=\"LIBPQ-CONNECT-GSSENCMODE\"\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003egssencmode\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\n\u003cp\u003eThis option determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server. There are three modes:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003edisable\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eonly try a non-GSSAPI-encrypted connection\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eprefer\u003c/code\u003e (default)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eif there are GSSAPI credentials present (i.e., in a credentials cache), first try a GSSAPI-encrypted connection; if that fails or there are no credentials, try a non-GSSAPI-encrypted connection. This is the default when \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e has been compiled with GSSAPI support.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003erequire\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eonly try a GSSAPI-encrypted connection\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003ccode class=\"literal\"\u003egssencmode\u003c/code\u003e is ignored for Unix domain socket communication. If \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e is compiled without GSSAPI support, using the \u003ccode class=\"literal\"\u003erequire\u003c/code\u003e option will cause an error, while \u003ccode class=\"literal\"\u003eprefer\u003c/code\u003e will be accepted but \u003cspan class=\"application\"\u003elibpq\u003c/span\u003e will not actually attempt a GSSAPI-encrypted connection.\u003c/p\u003e\n\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","related":[{"label":"Connection service file","url":"/docs/18/libpq-pgservice.html"},{"label":"Password file","url":"/docs/18/libpq-pgpass.html"},{"label":"All libpq environment variables","url":"/docs/18/libpq-envars.html"}],"sections":[{"paragraphs":["The following environment variables can be used to select default connection parameter values, which will be used by PQconnectdb , PQsetdbLogin and PQsetdb if no value is directly specified by the calling code. These are useful to avoid hard-coding database connection information into simple client applications, for example.","Service names can be defined in either a per-user service file or a system-wide file. If the same service name exists in both the user and the system file, the user file takes precedence. By default, the per-user service file is named ~/.pg_service.conf . On Microsoft Windows, it is named %APPDATA%\\postgresql\\.pg_service.conf (where %APPDATA% refers to the Application Data subdirectory in the user's profile). A different file name can be specified by setting the environment variable PGSERVICEFILE . The system-wide file is named pg_service.conf . By default it is sought in the etc directory of the PostgreSQL installation (use pg_config --sysconfdir to identify this directory precisely). Another directory, but not a different file name, can be specified by setting the environment variable PGSYSCONFDIR .","Connection parameters obtained from a service file are combined with parameters obtained from other sources. A service file setting overrides the corresponding environment variable, and in turn can be overridden by a value given directly in the connection string. For example, using the above service file, a connection string service=mydb port=5434 will use host somehost , port 5434 , user admin , and other parameters as set by environment variables or built-in defaults."],"title":"Default resolution and service-file precedence"},{"paragraphs":["PGGSSENCMODE behaves the same as the gssencmode connection parameter."],"title":"Environment variable evidence"}],"tables":[{"columns":[{"key":"name","label":"Variable"},{"key":"description","label":"Documented behavior"}],"key":"environment","rows":[{"description":"PGGSSENCMODE behaves the same as the gssencmode connection parameter.","name":{"text":"PGGSSENCMODE","url":"/docs/18/libpq-envars.html"}}],"title":"Environment fallback"}]}},"RequestedLocale":"zh-Hans","Fallback":true,"Versions":["12","13","14","15","16","17","18","19","20"],"Locales":["en"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}