{"Entry":{"collection":"metric","key":"pg_stat_recovery_prefetch-wal_distance","name":"pg_stat_recovery_prefetch.wal_distance","aliases":["wal_distance","pg_stat_recovery_prefetch"],"metadata":{"aliases":["wal_distance","pg_stat_recovery_prefetch"],"category":"pg_stat_recovery_prefetch","content_hash":"f352c507256e137809495f998e91dd4f62c2aad5cd69d3d2a314fed6a4862e60","derived_content_hash":"3eefa193da73e86a4c5b03e78c76f556b005289e31bd6578125623872d42eece","imported_at":"2026-09-30T00:40:46.054675+08:00","name":"pg_stat_recovery_prefetch.wal_distance","name_zh":"","slug":"pg_stat_recovery_prefetch-wal_distance","summary":"How many bytes ahead the prefetcher is looking"}},"Definition":{"Collection":"metric","Key":"pg_stat_recovery_prefetch-wal_distance","SourceDatabase":"center","Version":"18","SourceTable":"statistics_metric","SourceKey":"pg_stat_recovery_prefetch-wal_distance","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"comparison_data":{"field":"wal_distance","sql_type":"int","units_mentioned":["bytes"],"view":"pg_stat_recovery_prefetch"},"comparison_hash":"1727ba16ec1f46688679d30c8c54c1f9cc81c0a814f22be844fff6c3fcb55716","description":["How many bytes ahead the prefetcher is looking"],"description_zh":"预取器向前查看的字节数","description_zh_html":"\u003cp\u003epg_stat_recovery_prefetch.wal_distance 统计字段。\u003c/p\u003e\u003cdl\u003e\u003cdt\u003e视图\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003epg_stat_recovery_prefetch\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e字段\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003ewal_distance\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003eSQL 类型\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003eint\u003c/code\u003e\u003c/dd\u003e\u003c/dl\u003e\u003ch3\u003e同版本中文手册定义\u003c/h3\u003e\u003cp\u003e预取器向前查看的字节数\u003c/p\u003e\u003cp\u003e\u003ca href=\"/zh/docs/18/monitoring-stats.html#\"\u003e查看完整中文手册与上下文\u003c/a\u003e。\u003c/p\u003e","documented":true,"facts":[{"label":"View","value":"pg_stat_recovery_prefetch"},{"label":"Field","value":"wal_distance"},{"label":"SQL type","value":"int"},{"label":"Units named in the field definition","value":"bytes"},{"label":"Reset observation","value":"Time at which these statistics were last reset"}],"facts_zh":[{"label":"视图","value":"pg_stat_recovery_prefetch"},{"label":"字段","value":"wal_distance"},{"label":"SQL 类型","value":"int"},{"label":"字段定义记载的单位","value":"bytes"},{"label":"重置条件","value":"这些统计上次重置的时间"}],"field":"wal_distance","manual_html":"","manual_path":"/docs/18/monitoring-stats.html","related":[{"label":"pg_stat_recovery_prefetch columns","url":"/wiki/catalog/pg_stat_recovery_prefetch/?v=18"},{"label":"Statistics collection and reset functions","url":"/docs/18/monitoring-stats.html"}],"release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[{"paragraphs":["The pg_stat_recovery_prefetch view will contain only one row. The columns wal_distance, block_distance and io_depth show current values, and the other columns show cumulative counters that can be reset with the pg_stat_reset_shared function."],"title":"View semantics"},{"paragraphs":["The pg_stat_recovery_prefetch view will contain only one row. 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The columns wal_distance, block_distance and io_depth show current values, and the other columns show cumulative counters that can be reset with the pg_stat_reset_shared function."],"title":"View semantics"},{"paragraphs":["The pg_stat_recovery_prefetch view will contain only one row. The columns wal_distance , block_distance and io_depth show current values, and the other columns show cumulative counters that can be reset with the pg_stat_reset_shared function."],"title":"Collection and reset context"},{"code":"SELECT wal_distance FROM pg_catalog.pg_stat_recovery_prefetch;","paragraphs":["Example query; no execution result or measured value is asserted."],"title":"Inspect this field"}],"tables":[]}},"RequestedLocale":"en","Fallback":false,"Versions":["15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}