{"Entry":{"collection":"guc","key":"max_function_args","name":"max_function_args","aliases":[],"metadata":{"baseline":false,"boot_human":"Not specified","boot_val":null,"category":"Preset Options","category_zh":"","changed_in":[],"changes":[{"documentation_changed":false,"fields":{},"from":"7.4","status":"added","to":"8.0"},{"documentation_changed":true,"fields":{},"from":"8.0","status":"changed","to":"8.1"},{"documentation_changed":true,"fields":{},"from":"8.1","status":"changed","to":"8.2"}],"content_hash":"4737071d48f3807ed5717826bde752608a7130b0a2c617024892775355c3639e","context":"","default_changed_in":[],"default_history":[{"from":"9.0","to":"19","value":"100"}],"editorial":{"advice":{"olap":"Not tunable. Use max_function_args to verify format, build, or resource assumptions on analytical nodes and keep every read/write candidate compatible.","oltp":"Not tunable. Record max_function_args as a deployment/capability fact; if it is unexpected, fix the binary, initdb, or database-creation process rather than trying SET.","small":"Not tunable. Preserve it in inventory and incident reports; do not custom-build or rebuild merely to change it without a demonstrated compatibility need."},"mechanism":["Shows the maximum number of function arguments. It is read-only and cannot be changed with SET or configuration-file edits.","It exposes the FUNC_MAX_ARGS build constant; changing it requires a compatible custom build, not a configuration edit.","Interpret it with max_identifier_length, max_index_keys, block_size. Applications and operations tooling may read max_function_args for capability or environment detection, but cannot SET it; cross-cluster comparisons must account for build, initdb, and current-database differences."],"pitfalls":["Trying to change read-only max_function_args with SET or a configuration file.","Assuming every cluster, database, or vendor build reports the same value.","Ignoring the value in file-format or feature-compatibility checks.","Treating reported metadata as a performance target instead of an environment fact."],"references":[{"title":"PostgreSQL 19 Beta 4: max_function_args","url":"https://www.postgresql.org/docs/19/runtime-config-preset.html#GUC-MAX-FUNCTION-ARGS"},{"title":"PostgreSQL 19 release notes","url":"https://www.postgresql.org/docs/19/release-19.html"}],"related":["max_identifier_length","max_index_keys","block_size","server_version_num","data_checksums","data_directory_mode"],"summary":"max_function_args — Shows the maximum number of function arguments. Observed in PG9.0–19 Beta 4; its last measured boot default is 100 in PG19 Beta 4, with internal context. This is a beta-snapshot fact and can change before PostgreSQL 19 GA."},"enumvals":[],"first_version":"8.0","group":"Preset Options","group_slug":"preset","imported_at":"2026-09-27T17:57:31.690221+08:00","intro_commit":{},"key":"max_function_args","last_version":"20","max_val":"","min_val":"","name":"max_function_args","position":267,"present_in":["8.0","8.1","8.2","8.3","8.4","9.0","9.1","9.2","9.3","9.4","9.5","9.6","10","11","12","13","14","15","16","17","18","19","20"],"short_desc":"Reports the maximum number of function arguments.","short_desc_zh":"","source_rev":"english-manuals:c10dc86d47fece60bb93ff26c08e354fd77a5053e2d0904a8f028335d570de50","unit":"","vartype":"integer"}},"Definition":{"Collection":"guc","Key":"max_function_args","SourceDatabase":"center","Version":"18","SourceTable":"guc","SourceKey":"max_function_args","SourceRevision":"english-manuals:c10dc86d47fece60bb93ff26c08e354fd77a5053e2d0904a8f028335d570de50","Facts":{"boot_val":"100","category":"Preset Options","context":"internal","description":"Reports the maximum number of function arguments. It is determined by the value of FUNC_MAX_ARGS when building the server. The default value is 100 arguments.","doc":{"anchor":"GUC-MAX-FUNCTION-ARGS","file":"runtime-config-preset.html","lang":"en","sha256":"4dbfec727b9cee838adefb8a766217748d91ab90190b452a58cec737459582ce","slug":"18"},"documented":true,"enumvals":null,"extra_desc":null,"lang":"en","max_val":"100","metadata_version":"18","min_val":"100","name":"max_function_args","short_desc":"Shows the maximum number of function arguments.","source":"pg-settings-source-snapshot","unit":null,"vartype":"integer"},"ManualEvidence":{"doc":{"anchor":"GUC-MAX-FUNCTION-ARGS","file":"runtime-config-preset.html","lang":"en","sha256":"4dbfec727b9cee838adefb8a766217748d91ab90190b452a58cec737459582ce","slug":"18"}},"MeasuredEvidence":{"metadata_version":"18"}},"Text":{"Collection":"guc","Key":"max_function_args","SourceDatabase":"center","Version":"18","Locale":"en","Title":"max_function_args","Summary":"Reports the maximum number of function arguments. It is determined by the value of FUNC_MAX_ARGS when building the server. The default value is 100 arguments.","BodyHTML":"\u003cp\u003eReports the maximum number of function arguments. It is determined by the value of FUNC_MAX_ARGS when building the server. The default value is 100 arguments.\u003c/p\u003e","SourceRevision":"english-manuals:c10dc86d47fece60bb93ff26c08e354fd77a5053e2d0904a8f028335d570de50","ContentHash":"56e65327f754a5fd2919431a294cee5e85c4401b271f72043d38c5fc85e70745","Payload":{"description":"Reports the maximum number of function arguments. It is determined by the value of FUNC_MAX_ARGS when building the server. The default value is 100 arguments."}},"RequestedLocale":"zh-Hans","Fallback":true,"Versions":["10","11","12","13","14","15","16","17","18","19","20","8.0","8.1","8.2","8.3","8.4","9.0","9.1","9.2","9.3","9.4","9.5","9.6"],"Locales":["en"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}