PostgreSQL参数—checkpoint_timeout

PostgreSQL参数—checkpoint_timeout

参数说明

postgres=# show checkpoint_timeout;

 checkpoint_timeout 
--------------------

 5min
(1 row)

postgres=# \x 
Expanded display is on.
postgres=# select * from pg_settings where name ='checkpoint_timeout';
-[ RECORD 1 ]---+---------------------------------------------------------
name            | checkpoint_timeout
setting         | 300
unit            | s
category        | Write-Ahead Log / Checkpoints
short_desc      | Sets the maximum time between automatic WAL checkpoints.
extra_desc      | 
context         | sighup
vartype         | integer
source          | default
min_val         | 30
max_val         | 86400
enumvals        | 
boot_val        | 300
reset_val       | 300
sourcefile      | 
sourceline      | 
pending_restart | f

postgres=# 

注1：postgresql.conf无需重新启动服务器即可更改这些设置。向 postmaster发送SIGHUP信号，使其重新读取postgresql.conf并应用更改。postmaster 还会将SIGHUP信号转发给它的子进程，以便它们都获得新值。

参数设置

postgres=# alter system set checkpoint_timeout = 600;
ALTER SYSTEM
postgres=# show checkpoint_timeout;
 checkpoint_timeout 
--------------------
 5min
(1 row)

postgres=# select pg_reload_conf();
 pg_reload_conf 
----------------
 t
(1 row)

postgres=# show checkpoint_timeout;
 checkpoint_timeout 
--------------------
 10min
(1 row)

postgres=# 

参数含义

系统自动执行checkpoint之间的最大时间间隔，同样间隔越大介质恢复的时间越长。系统默认值是5分钟。