{"Entry":{"collection":"guc","key":"bgwriter_all_percent","name":"bgwriter_all_percent","aliases":[],"metadata":{"baseline":false,"boot_human":"Not specified","boot_val":null,"category":"Resource Usage","category_zh":"","changed_in":[],"changes":[{"documentation_changed":false,"fields":{},"from":"8.0","status":"added","to":"8.1"},{"documentation_changed":true,"fields":{},"from":"8.1","status":"changed","to":"8.2"},{"documentation_changed":false,"fields":{},"from":"8.2","status":"removed","to":"8.3"}],"content_hash":"3efecf7e4174f9d30ad5fdbd8fd50e60d90b3e4fdb68d21734620bea08871fd9","context":"","default_changed_in":[],"default_history":[],"editorial":{},"enumvals":[],"first_version":"8.1","group":"Resource Usage","group_slug":"resource","imported_at":"2026-09-27T17:57:30.8708+08:00","intro_commit":{},"key":"bgwriter_all_percent","last_version":"8.2","max_val":"","min_val":"","name":"bgwriter_all_percent","position":42,"present_in":["8.1","8.2"],"short_desc":"To reduce the amount of work that will be needed at checkpoint time, the background writer also does a circular scan through the entire buffer pool, writing buffers that are found to be dirty.","short_desc_zh":"","source_rev":"english-manuals:352c41f450552819bff54df127645a9eb2bc15211696723c96083da9acdbefe8","unit":"","vartype":"real"}},"Definition":{"Collection":"guc","Key":"bgwriter_all_percent","SourceDatabase":"center","Version":"8.2","SourceTable":"guc","SourceKey":"bgwriter_all_percent","SourceRevision":"english-manuals:352c41f450552819bff54df127645a9eb2bc15211696723c96083da9acdbefe8","Facts":{"boot_val":null,"category":"Background Writer","context":"","description":"To reduce the amount of work that will be needed at checkpoint time, the background writer also does a circular scan through the entire buffer pool, writing buffers that are found to be dirty. In each round, it examines up to bgwriter_all_percent of the buffers for this purpose. The default value is 0.333 (0.333% of the total number of shared buffers). With the default bgwriter_delay setting, this will allow the entire shared buffer pool to be scanned about once per minute. This parameter can only be set in the postgresql.conf file or on the server command line.","doc":{"anchor":"GUC-BGWRITER-ALL-PERCENT","file":"runtime-config-resource.html","lang":"en","sha256":"58e7050a55a788769e3cb0bb328aebf1aeb4d49b4cc7e101c0c375786ccb870c","slug":"8.2"},"documented":true,"enumvals":[],"extra_desc":"","lang":"en","max_val":null,"metadata_version":"","min_val":null,"name":"bgwriter_all_percent","short_desc":"","source":"english-manual","unit":"","vartype":"real"},"ManualEvidence":{"doc":{"anchor":"GUC-BGWRITER-ALL-PERCENT","file":"runtime-config-resource.html","lang":"en","sha256":"58e7050a55a788769e3cb0bb328aebf1aeb4d49b4cc7e101c0c375786ccb870c","slug":"8.2"}},"MeasuredEvidence":{"metadata_version":""}},"Text":{"Collection":"guc","Key":"bgwriter_all_percent","SourceDatabase":"center","Version":"8.2","Locale":"en","Title":"bgwriter_all_percent","Summary":"To reduce the amount of work that will be needed at checkpoint time, the background writer also does a circular scan through the entire buffer pool, writing buffers that are found to be dirty. In each round, it examines up to bgwriter_all_percent of the buffers for this purpose. The default value is 0.333 (0.333% of the total number of shared buffers). With the default bgwriter_delay setting, this will allow the entire shared buffer pool to be scanned about once per minute. This parameter can only be set in the postgresql.conf file or on the server command line.","BodyHTML":"\u003cp\u003eTo reduce the amount of work that will be needed at checkpoint time, the background writer also does a circular scan through the entire buffer pool, writing buffers that are found to be dirty. In each round, it examines up to bgwriter_all_percent of the buffers for this purpose. The default value is 0.333 (0.333% of the total number of shared buffers). With the default bgwriter_delay setting, this will allow the entire shared buffer pool to be scanned about once per minute. This parameter can only be set in the postgresql.conf file or on the server command line.\u003c/p\u003e","SourceRevision":"english-manuals:352c41f450552819bff54df127645a9eb2bc15211696723c96083da9acdbefe8","ContentHash":"00fe1ae183397a68eb357e798ec34a15565c4924e7adc3dd68a539f11852761e","Payload":{"description":"To reduce the amount of work that will be needed at checkpoint time, the background writer also does a circular scan through the entire buffer pool, writing buffers that are found to be dirty. In each round, it examines up to bgwriter_all_percent of the buffers for this purpose. The default value is 0.333 (0.333% of the total number of shared buffers). With the default bgwriter_delay setting, this will allow the entire shared buffer pool to be scanned about once per minute. This parameter can only be set in the postgresql.conf file or on the server command line."}},"RequestedLocale":"zh-Hans","Fallback":true,"Versions":["8.1","8.2"],"Locales":["en"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}