pg_stat_checkpointer 是一个 统计视图，用于显示有关 检查点 的信息。
pg_stat_checkpointer 添加于 PostgreSQL 17，它整合了之前包含在 pg_stat_bgwriter 中的部分信息。
统计重置
pg_stat_checkpointer 显示的统计信息可以通过执行以下命令来重置：
SELECT pg_stat_reset_shared('checkpointer')
按 PostgreSQL 版本定义
pg_stat_checkpointer (PostgreSQL 19)
View "pg_catalog.pg_stat_checkpointer"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
num_timed | bigint | | |
num_requested | bigint | | |
num_done | bigint | | |
restartpoints_timed | bigint | | |
restartpoints_req | bigint | | |
restartpoints_done | bigint | | |
write_time | double precision | | |
sync_time | double precision | | |
buffers_written | bigint | | |
slru_written | bigint | | |
stats_reset | timestamp with time zone | | |
pg_stat_checkpointer (PostgreSQL 18)
View "pg_catalog.pg_stat_checkpointer"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
num_timed | bigint | | |
num_requested | bigint | | |
num_done | bigint | | |
restartpoints_timed | bigint | | |
restartpoints_req | bigint | | |
restartpoints_done | bigint | | |
write_time | double precision | | |
sync_time | double precision | | |
buffers_written | bigint | | |
slru_written | bigint | | |
stats_reset | timestamp with time zone | | |
pg_stat_checkpointer (PostgreSQL 17)
View "pg_catalog.pg_stat_checkpointer"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
num_timed | bigint | | |
num_requested | bigint | | |
restartpoints_timed | bigint | | |
restartpoints_req | bigint | | |
restartpoints_done | bigint | | |
write_time | double precision | | |
sync_time | double precision | | |
buffers_written | bigint | | |
stats_reset | timestamp with time zone | | |
变更历史
- PostgreSQL 18
- 添加了列
num_done(提交 559efce1)
- 添加了列
- PostgreSQL 17
- 添加（提交 96f05261）
示例
pg_stat_checkpointer 的基本用法示例
postgres=# SELECT * FROM pg_stat_checkpointer;
num_timed | num_requested | write_time | sync_time | buffers_written | stats_reset
-----------+---------------+------------+-----------+-----------------+-------------------------------
1 | 1 | 4514 | 2 | 76 | 2023-10-31 10:31:48.064606+09
(1 row)
postgres=# CHECKPOINT;
CHECKPOINT
postgres=# SELECT * FROM pg_stat_checkpointer;
num_timed | num_requested | write_time | sync_time | buffers_written | stats_reset
-----------+---------------+------------+-----------+-----------------+-------------------------------
1 | 2 | 4516 | 3 | 76 | 2023-10-31 10:31:48.064606+09
(1 row)
重置 pg_stat_checkpointer 统计信息
postgres=# SELECT pg_stat_reset_shared('checkpointer');
pg_stat_reset_shared
----------------------
(1 row)
postgres=# SELECT * FROM pg_stat_checkpointer;
num_timed | num_requested | write_time | sync_time | buffers_written | stats_reset
-----------+---------------+------------+-----------+-----------------+-------------------------------
0 | 0 | 0 | 0 | 0 | 2023-10-31 10:48:28.553766+09
(1 row)
参考资料
- PostgreSQL 文档: pg_stat_checkpointer
有用链接
- PostgreSQL 17：新的目录视图 pg_stat_checkpointer - Daniel Westermann 的 2023 年 11 月博客文章