pg_stat_reset_backend_stats()
是一个系统函数,用于将单个后端的统计信息重置为零。
pg_stat_reset_backend_stats()
在 PostgreSQL 18 中添加。
示例
pg_stat_reset_backend_stats()
的基本用法示例
postgres=# SELECT object, context, reads, extends, op_bytes, hits, stats_reset FROM pg_stat_get_backend_io( pg_backend_pid() ); object | context | reads | extends | op_bytes | hits | stats_reset ---------------+-----------+-------+---------+----------+------+------------- relation | bulkread | 0 | | 8192 | 0 | relation | bulkwrite | 0 | 0 | 8192 | 0 | relation | normal | 2490 | 0 | 8192 | 3065 | relation | vacuum | 0 | 0 | 8192 | 0 | temp relation | normal | 0 | 0 | 8192 | 0 | (5 rows) postgres=# SELECT pg_stat_reset_backend_stats( pg_backend_pid() ); pg_stat_reset_backend_stats ----------------------------- (1 row) postgres=# SELECT object, context, reads, extends, op_bytes, hits, stats_reset FROM pg_stat_get_backend_io( pg_backend_pid() ); object | context | reads | extends | op_bytes | hits | stats_reset ---------------+-----------+-------+---------+----------+------+------------------------------- relation | bulkread | 0 | | 8192 | 0 | 2024-12-20 11:07:24.408795+09 relation | bulkwrite | 0 | 0 | 8192 | 0 | 2024-12-20 11:07:24.408795+09 relation | normal | 1 | 0 | 8192 | 8 | 2024-12-20 11:07:24.408795+09 relation | vacuum | 0 | 0 | 8192 | 0 | 2024-12-20 11:07:24.408795+09 temp relation | normal | 0 | 0 | 8192 | 0 | 2024-12-20 11:07:24.408795+09 (5 rows)
提供一个不存在的后端 ID 不会产生任何警告或错误
postgres=# SELECT pg_stat_reset_backend_stats( 999 ); pg_stat_reset_backend_stats ----------------------------- (1 row)
参考资料
- PostgreSQL 文档: 其他统计信息函数