Postgresql 中文操作指南

53.5. pg_amproc #

目录 pg_amproc 存储与访问方法运算符族关联的支持函数的信息。对于属于运算符族中的每个支持函数，都有一行。

The catalog pg_amproc stores information about support functions associated with access method operator families. There is one row for each support function belonging to an operator family.

Table 53.5. pg_amproc Columns

Column Type

Description

oid oid

Row identifier

amprocfamily oid (references pg_opfamily.oid)

The operator family this entry is for

amproclefttype oid (references pg_type.oid)

Left-hand input data type of associated operator

amprocrighttype oid (references pg_type.oid)

Right-hand input data type of associated operator

amprocnum int2

Support function number

amproc regproc (references pg_proc.oid)

OID of the function

@{11} 和 amprocrighttype 域通常被解释为标识特定支持函数所支持的运算符的左右输入类型。对于某些访问方法，它们与支持函数自己的输入数据类型匹配，而对于其他访问方法则不匹配。“默认”支持函数的概念适用于索引，其 amproclefttype 和 amprocrighttype 均等于索引运算符类的 opcintype。

The usual interpretation of the amproclefttype and amprocrighttype fields is that they identify the left and right input types of the operator(s) that a particular support function supports. For some access methods these match the input data type(s) of the support function itself, for others not. There is a notion of “default” support functions for an index, which are those with amproclefttype and amprocrighttype both equal to the index operator class’s opcintype.