Wiki / 配置参数

Ask the kernel to minimize caching effects for relation data and WAL files using O_DIRECT (most Unix-like systems), F_NOCACHE (macOS) or FILE_FLAG_NO_BUFFERING (Windows). May be set to an empty string (the default) to disable use of direct I/O, or a comma-separated list of operations that should use direct I/O. The valid options are data for main data files, wal for WAL files, and wal_init for WAL files when being initially allocated. This parameter can only be set at server start. Some operating systems and file systems do not support direct I/O, so non-default settings may be rejected at startup or cause errors. Currently this feature reduces performance, and is intended for developer testing only.

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。

此版本暂无所选语言的定义，以下显示原始英文内容。

boot val

未知

category

Developer Options

context

postmaster

documented

true

enumvals

未知

extra desc

An empty string disables direct I/O.

lang

en

max val

未知

metadata version

18

min val

未知

name

debug_io_direct

short desc

Use direct I/O for file access.

source

pg-settings-source-snapshot

unit

未知

vartype

string