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pg_backend_memory_contexts

PostgreSQL 官方文档 ↗

The view pg_backend_memory_contexts displays all the memory contexts of the server process attached to the current session. pg_backend_memory_contexts contains one row for each memory context.

首次收录 PG 14最近收录 PG 19当前字段 10
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_backend_memory_contexts
字段 / COLUMN类型 / TYPE说明 / DESCRIPTION
name text Name of the memory context
ident text Identification information of the memory context. This field is truncated at 1024 bytes
type text Type of the memory context
level integer文档原写法：int4 The 1-based level of the context in the memory context hierarchy. The level of a context also shows the position of that context in the path column.
path integer[]文档原写法：int4[] Array of transient numerical identifiers to describe the memory context hierarchy. The first element is for TopMemoryContext, subsequent elements contain intermediate parents and the final element contains the identifier for the current context.
total_bytes bigint文档原写法：int8 Total bytes allocated for this memory context
total_nblocks bigint文档原写法：int8 Total number of blocks allocated for this memory context
free_bytes bigint文档原写法：int8 Free space in bytes
free_chunks bigint文档原写法：int8 Total number of free chunks
used_bytes bigint文档原写法：int8 Used space in bytes

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
name – – – – – – – – – – –
ident – – – – – – – – – – –
parent – – – – – – – – – – – − –
level – – – – – – – – – – –
total_bytes – – – – – – – – – – –
total_nblocks – – – – – – – – – – –
free_bytes – – – – – – – – – – –
free_chunks – – – – – – – – – – –
used_bytes – – – – – – – – – – –
type – – – – – – – – – – – – – – –
path – – – – – – – – – – – – – – –

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

+ type+ path− parent1 处字段说明更新

PostgreSQL 14 ← 13新增目录

+ name+ ident+ parent+ level+ total_bytes+ total_nblocks+ free_bytes+ free_chunks+ used_bytes

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。