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pg_aios

PostgreSQL 官方文档 ↗

The pg_aios view lists all Asynchronous I/O handles that are currently in-use. An I/O handle is used to reference an I/O operation that is being prepared, executed or is in the process of completing. pg_aios contains one row for each I/O handle. This view is mainly useful for developers of PostgreSQL, but may also be useful when tuning PostgreSQL.

首次收录 PG 18最近收录 PG 19当前字段 15
9.09.19.29.39.49.59.610111213141516171819β3

已与 PostgreSQL 18.6 实例逐字段核对 · 原始实测记录 ↗

字段结构 PostgreSQL 18

pg_aios
字段 / COLUMN类型 / TYPE说明 / DESCRIPTION
pid integer文档原写法：int4 Process ID of the server process that is issuing this I/O.
io_id integer文档原写法：int4 Identifier of the I/O handle. Handles are reused once the I/O completed (or if the handle is released before I/O is started). On reuse pg_aios.io_generation is incremented.
io_generation bigint文档原写法：int8 Generation of the I/O handle.
state text State of the I/O handle:
operation text Operation performed using the I/O handle:
off bigint文档原写法：int8 Offset of the I/O operation.
length bigint文档原写法：int8 Length of the I/O operation.
target text What kind of object is the I/O targeting:
handle_data_len smallint文档原写法：int2 Length of the data associated with the I/O operation. For I/O to/from shared_buffers and temp_buffers, this indicates the number of buffers the I/O is operating on.
raw_result integer文档原写法：int4 Low-level result of the I/O operation, or NULL if the operation has not yet completed.
result text High-level result of the I/O operation:
target_desc text Description of what the I/O operation is targeting.
f_sync boolean文档原写法：bool Flag indicating whether the I/O is executed synchronously.
f_localmem boolean文档原写法：bool Flag indicating whether the I/O references process local memory.
f_buffered boolean文档原写法：bool Flag indicating whether the I/O is buffered I/O.

标记“隐式列”的字段不包含在 SELECT * 中；部分早期统计视图由同版本源码补全，额外来源会显示在字段说明中。

字段演化矩阵

悬停查看字段类型
存在新增 / 类型或属性变化移除
字段 / COLUMN9.09.19.29.39.49.59.610111213141516171819
pid – – – – – – – – – – – – – – –
io_id – – – – – – – – – – – – – – –
io_generation – – – – – – – – – – – – – – –
state – – – – – – – – – – – – – – –
operation – – – – – – – – – – – – – – –
off – – – – – – – – – – – – – – –
length – – – – – – – – – – – – – – –
target – – – – – – – – – – – – – – –
handle_data_len – – – – – – – – – – – – – – –
raw_result – – – – – – – – – – – – – – –
result – – – – – – – – – – – – – – –
target_desc – – – – – – – – – – – – – – –
f_sync – – – – – – – – – – – – – – –
f_localmem – – – – – – – – – – – – – – –
f_buffered – – – – – – – – – – – – – – –

9.0 是收录基线；基线中已存在的字段不标记为新增。矩阵按字段名称对齐，重命名显示为旧字段移除与新字段新增。

演化时间线

相邻大版本的变化

PostgreSQL 18 ← 17新增目录

+ pid+ io_id+ io_generation+ state+ operation+ off+ length+ target+ handle_data_len+ raw_result+ result+ target_desc+ f_sync+ f_localmem+ f_buffered

比较任意两个版本

选择两个版本，查看字段的新增、移除与类型变化。交互比较需要 JavaScript；演化时间线可直接阅读。