SYSTEM CATALOG · 系统目录

pg_statistic_ext

The catalog pg_statistic_ext holds definitions of extended planner statistics. Each row in this catalog corresponds to a statistics object created with CREATE STATISTICS.

首次收录 PG 10最近收录 PG 19当前字段 9

9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19^β3

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_statistic_ext

字段 / COLUMN	类型 / TYPE	说明 / DESCRIPTION
`oid`	`oid`NOT NULL	Row identifier
`stxrelid`	`oid`NOT NULL	Table containing the columns described by this object引用：`pg_class.oid`
`stxname`	`name`NOT NULL	Name of the statistics object
`stxnamespace`	`oid`NOT NULL	The OID of the namespace that contains this statistics object引用：`pg_namespace.oid`
`stxowner`	`oid`NOT NULL	Owner of the statistics object引用：`pg_authid.oid`
`stxkeys`	`int2vector`NOT NULL	An array of attribute numbers, indicating which table columns are covered by this statistics object; for example a value of 1 3 would mean that the first and the third table columns are covered引用：`pg_attribute.attnum`
`stxstattarget`	`smallint`文档原写法：`int2`	stxstattarget controls the level of detail of statistics accumulated for this statistics object by ANALYZE. A zero value indicates that no statistics should be collected. A null value says to use the maximum of the statistics targets of the referenced columns, if set, or the system default statistics target. Positive values of stxstattarget determine the target number of “most common values” to collect.
`stxkind`	`"char"[]`NOT NULL文档原写法：`char[]`	An array containing codes for the enabled statistics kinds; valid values are: d for n-distinct statistics, f for functional dependency statistics, m for most common values (MCV) list statistics, and e for expression statistics
`stxexprs`	`pg_node_tree`	Expression trees (in nodeToString() representation) for statistics object attributes that are not simple column references. This is a list with one element per expression. Null if all statistics object attributes are simple references.

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。

通用系统列 6

PostgreSQL 提供的系统属性，通常不在 SELECT * 中展开。单独保留，不与普通字段混算。

字段	类型	attnum
`tableoid`	`oid`	-6
`cmax`	`cid`	-5
`xmax`	`xid`	-4
`cmin`	`cid`	-3
`xmin`	`xid`	-2
`ctid`	`tid`	-1

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 / COLUMN	9.0	9.1	9.2	9.3	9.4	9.5	9.6	10	11	12	13	14	15	16	17	18	19
`oid`	–	–	–	–	–	–	–
`stxrelid`	–	–	–	–	–	–	–
`stxname`	–	–	–	–	–	–	–
`stxnamespace`	–	–	–	–	–	–	–
`stxowner`	–	–	–	–	–	–	–
`stxkeys`	–	–	–	–	–	–	–
`stxkind`	–	–	–	–	–	–	–
`stxndistinct`	–	–	–	–	–	–	–			−	–	–	–	–	–	–	–
`stxdependencies`	–	–	–	–	–	–	–			−	–	–	–	–	–	–	–
`stxstattarget`	–	–	–	–	–	–	–	–	–	–
`stxexprs`	–	–	–	–	–	–	–	–	–	–	–

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 17 ← 16

~ stxstattarget: integer → smallint~ stxstattarget: not_null: true → false↕ 字段顺序变化1 处字段说明更新

PostgreSQL 14 ← 13

+ stxexprs1 处字段说明更新

PostgreSQL 13 ← 12

+ stxstattarget1 处字段说明更新

PostgreSQL 12 ← 11

− stxndistinct− stxdependencies~ oid: 隐式列 → 常规列2 处字段说明更新目录说明更新

PostgreSQL 10 ← 9.6新增目录

+ oid+ stxrelid+ stxname+ stxnamespace+ stxowner+ stxkeys+ stxkind+ stxndistinct+ stxdependencies

比较任意两个版本

起始版本 / FROM目标版本 / TO包含描述更新

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。