{
    "content": [
        {
            "type": "text",
            "text": "# ALTER_SYSTEM(7) (man)\n\n**Summary:** ALTERSYSTEM - change a server configuration parameter\n\n**Synopsis:** ALTER SYSTEM SET configurationparameter { TO | = } { value [, ...] | DEFAULT }\nALTER SYSTEM RESET configurationparameter\nALTER SYSTEM RESET ALL\n\n## Examples\n\n- `Set the wallevel:`\n- `ALTER SYSTEM SET wallevel = replica;`\n- `Undo that, restoring whatever setting was effective in postgresql.conf:`\n- `ALTER SYSTEM RESET wallevel;`\n\n## See Also\n\n- SET(7)\n- SHOW(7)\n- SYSTEM(7)\n\n## Section Outline\n\n- **NAME** (2 lines)\n- **SYNOPSIS** (5 lines)\n- **DESCRIPTION** (16 lines)\n- **PARAMETERS** (14 lines)\n- **NOTES** (5 lines)\n- **EXAMPLES** (8 lines)\n- **COMPATIBILITY** (2 lines)\n- **SEE ALSO** (5 lines)\n\n## Full Content\n\n### NAME\n\nALTERSYSTEM - change a server configuration parameter\n\n### SYNOPSIS\n\nALTER SYSTEM SET configurationparameter { TO | = } { value [, ...] | DEFAULT }\n\nALTER SYSTEM RESET configurationparameter\nALTER SYSTEM RESET ALL\n\n### DESCRIPTION\n\nALTER SYSTEM is used for changing server configuration parameters across the entire database\ncluster. It can be more convenient than the traditional method of manually editing the\npostgresql.conf file.  ALTER SYSTEM writes the given parameter setting to the\npostgresql.auto.conf file, which is read in addition to postgresql.conf. Setting a parameter\nto DEFAULT, or using the RESET variant, removes that configuration entry from the\npostgresql.auto.conf file. Use RESET ALL to remove all such configuration entries.\n\nValues set with ALTER SYSTEM will be effective after the next server configuration reload, or\nafter the next server restart in the case of parameters that can only be changed at server\nstart. A server configuration reload can be commanded by calling the SQL function\npgreloadconf(), running pgctl reload, or sending a SIGHUP signal to the main server\nprocess.\n\nOnly superusers can use ALTER SYSTEM. Also, since this command acts directly on the file\nsystem and cannot be rolled back, it is not allowed inside a transaction block or function.\n\n### PARAMETERS\n\nconfigurationparameter\nName of a settable configuration parameter. Available parameters are documented in\nChapter 20.\n\nvalue\nNew value of the parameter. Values can be specified as string constants, identifiers,\nnumbers, or comma-separated lists of these, as appropriate for the particular parameter.\nValues that are neither numbers nor valid identifiers must be quoted.  DEFAULT can be\nwritten to specify removing the parameter and its value from postgresql.auto.conf.\n\nFor some list-accepting parameters, quoted values will produce double-quoted output to\npreserve whitespace and commas; for others, double-quotes must be used inside\nsingle-quoted strings to get this effect.\n\n### NOTES\n\nThis command can't be used to set datadirectory, nor parameters that are not allowed in\npostgresql.conf (e.g., preset options).\n\nSee Section 20.1 for other ways to set the parameters.\n\n### EXAMPLES\n\nSet the wallevel:\n\nALTER SYSTEM SET wallevel = replica;\n\nUndo that, restoring whatever setting was effective in postgresql.conf:\n\nALTER SYSTEM RESET wallevel;\n\n### COMPATIBILITY\n\nThe ALTER SYSTEM statement is a PostgreSQL extension.\n\n### SEE ALSO\n\nSET(7), SHOW(7)\n\n\n\nPostgreSQL 14.23                                2026                                 ALTER SYSTEM(7)\n\n"
        }
    ],
    "structuredContent": {
        "command": "ALTER_SYSTEM",
        "section": "7",
        "mode": "man",
        "summary": "ALTERSYSTEM - change a server configuration parameter",
        "synopsis": "ALTER SYSTEM SET configurationparameter { TO | = } { value [, ...] | DEFAULT }\nALTER SYSTEM RESET configurationparameter\nALTER SYSTEM RESET ALL",
        "tldr_summary": null,
        "tldr_examples": [],
        "tldr_source": null,
        "flags": [],
        "examples": [
            "Set the wallevel:",
            "ALTER SYSTEM SET wallevel = replica;",
            "Undo that, restoring whatever setting was effective in postgresql.conf:",
            "ALTER SYSTEM RESET wallevel;"
        ],
        "see_also": [
            {
                "name": "SET",
                "section": "7",
                "url": "https://www.chedong.com/phpMan.php/man/SET/7/json"
            },
            {
                "name": "SHOW",
                "section": "7",
                "url": "https://www.chedong.com/phpMan.php/man/SHOW/7/json"
            },
            {
                "name": "SYSTEM",
                "section": "7",
                "url": "https://www.chedong.com/phpMan.php/man/SYSTEM/7/json"
            }
        ],
        "section_outline": [
            {
                "name": "NAME",
                "lines": 2,
                "subsections": []
            },
            {
                "name": "SYNOPSIS",
                "lines": 5,
                "subsections": []
            },
            {
                "name": "DESCRIPTION",
                "lines": 16,
                "subsections": []
            },
            {
                "name": "PARAMETERS",
                "lines": 14,
                "subsections": []
            },
            {
                "name": "NOTES",
                "lines": 5,
                "subsections": []
            },
            {
                "name": "EXAMPLES",
                "lines": 8,
                "subsections": []
            },
            {
                "name": "COMPATIBILITY",
                "lines": 2,
                "subsections": []
            },
            {
                "name": "SEE ALSO",
                "lines": 5,
                "subsections": []
            }
        ]
    }
}