PostgreSQL 17 ← 16
← 目录图谱 / pg_opclass
SYSTEM CATALOG · 系统目录
pg_opclass
The catalog pg_opclass defines index access method operator classes. Each operator class defines semantics for index columns of a particular data type and a particular index access method. An operator class essentially specifies that a particular operator family is applicable to a particular indexable column data type. The set of operators from the family that are actually usable with the indexed column are whichever ones accept the column's data type as their left-hand input. Operator classes are described at length in Section 36.16.
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_opclassPostgreSQL 19 beta 3 是预发布快照，结构在正式发布前仍可能变化。
| 字段 / COLUMN | 类型 / TYPE | 说明 / DESCRIPTION |
|---|---|---|
oid |
oidNOT NULL |
Row identifier |
opcmethod |
oidNOT NULL |
Index access method operator class is for引用：pg_am.oid |
opcname |
nameNOT NULL |
Name of this operator class |
opcnamespace |
oidNOT NULL |
Namespace of this operator class引用：pg_namespace.oid |
opcowner |
oidNOT NULL |
Owner of the operator class引用：pg_authid.oid |
opcfamily |
oidNOT NULL |
Operator family containing the operator class引用：pg_opfamily.oid |
opcintype |
oidNOT NULL |
Data type that the operator class indexes引用：pg_type.oid |
opcdefault |
booleanNOT NULL文档原写法：bool |
True if this operator class is the default for opcintype |
opckeytype |
oidNOT NULL |
Type of data stored in index, or zero if same as opcintype引用：pg_type.oid |
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 |
|||||||||||||||||
opcmethod |
|||||||||||||||||
opcname |
|||||||||||||||||
opcnamespace |
|||||||||||||||||
opcowner |
|||||||||||||||||
opcfamily |
|||||||||||||||||
opcintype |
|||||||||||||||||
opcdefault |
|||||||||||||||||
opckeytype |
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 14 ← 13
PostgreSQL 12 ← 11
PostgreSQL 11 ← 10
PostgreSQL 10 ← 9.6
PostgreSQL 9.6 ← 9.5
PostgreSQL 9.3 ← 9.2
PostgreSQL 9.2 ← 9.1
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。