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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. 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If set to 0, compression will be disabled. The default is 0. This parameter is ignored if a connection without SSL is made.","BodyHTML":"\u003cdiv\u003e\u003cdl\u003e\u003cdt id=\"LIBPQ-CONNECT-SSLCOMPRESSION\"\u003e\u003cspan\u003e\u003ccode\u003esslcompression\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\n\u003cp\u003eIf set to 1, data sent over SSL connections will be compressed. If set to 0, compression will be disabled. The default is 0. This parameter is ignored if a connection without SSL is made.\u003c/p\u003e\n\u003cp\u003eSSL compression is nowadays considered insecure and its use is no longer recommended. \u003cspan\u003eOpenSSL\u003c/span\u003e 1.1.0 disabled compression by default, and many operating system distributions disabled it in prior versions as well, so setting this parameter to on will not have any effect if the server does not accept compression. \u003cspan\u003ePostgreSQL\u003c/span\u003e 14 disabled compression completely in the backend.\u003c/p\u003e\n\u003cp\u003eIf security is not a primary concern, compression can improve throughput if the network is the bottleneck. Disabling compression can improve response time and throughput if CPU performance is the limiting factor.\u003c/p\u003e\n\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","SourceRevision":"ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8","ContentHash":"767396d485b2e53cf34e81ceb695aeb0f914c55d8cf84156f5ca89fcfde53360","Payload":{"description":["If set to 1, data sent over SSL connections will be compressed. If set to 0, compression will be disabled. The default is 0. This parameter is ignored if a connection without SSL is made."],"manual_html":"\u003cdiv\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt id=\"LIBPQ-CONNECT-SSLCOMPRESSION\"\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003esslcompression\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\n\u003cp\u003eIf set to 1, data sent over SSL connections will be compressed. If set to 0, compression will be disabled. The default is 0. This parameter is ignored if a connection without SSL is made.\u003c/p\u003e\n\u003cp\u003eSSL compression is nowadays considered insecure and its use is no longer recommended. \u003cspan class=\"productname\"\u003eOpenSSL\u003c/span\u003e 1.1.0 disabled compression by default, and many operating system distributions disabled it in prior versions as well, so setting this parameter to on will not have any effect if the server does not accept compression. \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e 14 disabled compression completely in the backend.\u003c/p\u003e\n\u003cp\u003eIf security is not a primary concern, compression can improve throughput if the network is the bottleneck. Disabling compression can improve response time and throughput if CPU performance is the limiting factor.\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":["PGSSLCOMPRESSION behaves the same as the sslcompression connection parameter."],"title":"Environment variable evidence"}],"tables":[{"columns":[{"key":"name","label":"Variable"},{"key":"description","label":"Documented behavior"}],"key":"environment","rows":[{"description":"PGSSLCOMPRESSION behaves the same as the sslcompression connection parameter.","name":{"text":"PGSSLCOMPRESSION","url":"/docs/18/libpq-envars.html"}}],"title":"Environment fallback"}]}},"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}