pg_stat_slru 是一个 统计视图，用于显示缓存页面访问的信息。具体来说，它提供了一种监控使用 SLRU（简单最近最少使用）算法进行缓存淘汰的各种较小缓存的方法，最初旨在协助开发和基准测试。
pg_stat_slru 在 PostgreSQL 13 中被添加。
统计重置
由 pg_stat_slru 显示的单个或所有缓存统计信息可以通过执行以下命令重置：
SELECT pg_stat_reset_slru()
请注意，缓存名称在 PostgreSQL 17 中发生了更改；有关详细信息，请参阅 pg_stat_reset_slru()。
按 PostgreSQL 版本定义
pg_stat_slru (PostgreSQL 19)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
pg_stat_slru (PostgreSQL 18)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
pg_stat_slru (PostgreSQL 17)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
pg_stat_slru (PostgreSQL 16)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
pg_stat_slru (PostgreSQL 15)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
pg_stat_slru (PostgreSQL 14)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
pg_stat_slru (PostgreSQL 13)
View "pg_catalog.pg_stat_slru"
Column | Type | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
name | text | | |
blks_zeroed | bigint | | |
blks_hit | bigint | | |
blks_read | bigint | | |
blks_written | bigint | | |
blks_exists | bigint | | |
flushes | bigint | | |
truncates | bigint | | |
stats_reset | timestamp with time zone | | |
文档： pg_stat_slru
变更历史
- PostgreSQL 17
- SLRU 缓存重命名 (commit bcdfa5f2)
- PostgreSQL 13
- 添加 (commit 28cac71b)
示例
postgres=# SELECT * FROM pg_stat_slru;
name | blks_zeroed | blks_hit | blks_read | blks_written | blks_exists | flushes | truncates | stats_reset
-----------------+-------------+----------+-----------+--------------+-------------+---------+-----------+-------------------------------
CommitTs | 1 | 95 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
MultiXactMember | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
MultiXactOffset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
Notify | 1 | 5 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
Serial | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
Subtrans | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
Xact | 0 | 1131 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
other | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2021-11-03 11:08:05.213091+01
(8 rows)
参考资料
- PostgreSQL 文档： pg_stat_slru
有用链接
- CommitFest 条目： SLRU 统计