commit_delay
Setting commit_delay adds a time delay before a WAL flush is initiated. This can improve group commit throughput by allowing a larger number of transactions to commit via a single WAL flush, if system load is high enough that additional transactions become ready to commit within the given interval. However, it also increases latency by up to the commit_delay for each WAL flush. Because the delay is just wasted if no other transactions become ready to commit, a delay is only performed if at least commit_siblings other transactions are active when a flush is about to be initiated. Also, no delays are performed if fsync is disabled. If this value is specified without units, it is taken as microseconds. The default commit_delay is zero (no delay). Only superusers and users with the appropriate SET privilege can change this setting. In PostgreSQL releases prior to 9.3, commit_delay behaved differently and was much less effective: it affected only commits, rather than all WAL flushes, and waited for the entire configured delay even if the WAL flush was completed sooner. Beginning in PostgreSQL 9.3, the first process that becomes ready to flush waits for the configured interval, while subsequent processes wait only until the leader completes the flush operation.
英文手册覆盖始于 PostgreSQL 7.4. 来源历史与运行验证各自保留独立版本边界。
当前阅读 PG 18·选择有来源记录的版本
此版本暂无所选语言的定义，以下显示原始英文内容。
- boot val
- 0
- category
- Write-Ahead Log / Settings
- context
- superuser
- documented
- true
- enumvals
- 未知
- extra desc
- 未知
- lang
- en
- max val
- 100000
- metadata version
- 18
- min val
- 0
- name
- commit_delay
- short desc
- Sets the delay in microseconds between transaction commit and flushing WAL to disk.
- source
- pg-settings-source-snapshot
- unit
- 未知
- vartype
- integer
版本定义 PG 18
Setting commit_delay adds a time delay before a WAL flush is initiated. This can improve group commit throughput by allowing a larger number of transactions to commit via a single WAL flush, if system load is high enough that additional transactions become ready to commit within the given interval. However, it also increases latency by up to the commit_delay for each WAL flush. Because the delay is just wasted if no other transactions become ready to commit, a delay is only performed if at least commit_siblings other transactions are active when a flush is about to be initiated. Also, no delays are performed if fsync is disabled. If this value is specified without units, it is taken as microseconds. The default commit_delay is zero (no delay). Only superusers and users with the appropriate SET privilege can change this setting. In PostgreSQL releases prior to 9.3, commit_delay behaved differently and was much less effective: it affected only commits, rather than all WAL flushes, and waited for the entire configured delay even if the WAL flush was completed sooner. Beginning in PostgreSQL 9.3, the first process that becomes ready to flush waits for the configured interval, while subsequent processes wait only until the leader completes the flush operation.
比较版本
来源引用
定义来源
center · PostgreSQL 18 · english-manuals:eac2ac29747c2839645105fc24fc53de82ab0a9d6591ec2f01e9da2f7aac8ba6
正文语言: en · english-manuals:eac2ac29747c2839645105fc24fc53de82ab0a9d6591ec2f01e9da2f7aac8ba6