51.39. pg_proc

目錄 pg_proc 儲存了有關函數、程序、彙總函數和窗函數(統稱為 routines)的資訊。有關更多訊息,請參閱 CREATE FUNCTIONCREATE PROCEDURE第 37.3 節

如果 prokind 指示該項目是針對彙總函數的話,則 pg_aggregate 中應該也存在相對應的資料列。

Table 51.39. pg_proc Columns

Name

Type

References

Description

oid

oid

Row identifier

proname

name

Name of the function

pronamespace

oid

pg_namespace.oid

The OID of the namespace that contains this function

proowner

oid

pg_authid.oid

Owner of the function

prolang

oid

pg_language.oid

Implementation language or call interface of this function

procost

float4

Estimated execution cost (in units of cpu_operator_cost); if proretset, this is cost per row returned

prorows

float4

Estimated number of result rows (zero if not proretset)

provariadic

oid

pg_type.oid

Data type of the variadic array parameter's elements, or zero if the function does not have a variadic parameter

prosupport

regproc

pg_proc.oid

Optional planner support function for this function (see Section 37.11)

prokind

char

f for a normal function, p for a procedure, a for an aggregate function, or w for a window function

prosecdef

bool

Function is a security definer (i.e., a “setuid” function)

proleakproof

bool

The function has no side effects. No information about the arguments is conveyed except via the return value. Any function that might throw an error depending on the values of its arguments is not leak-proof.

proisstrict

bool

Function returns null if any call argument is null. In that case the function won't actually be called at all. Functions that are not “strict” must be prepared to handle null inputs.

proretset

bool

Function returns a set (i.e., multiple values of the specified data type)

provolatile

char

provolatile tells whether the function's result depends only on its input arguments, or is affected by outside factors. It is i for “immutable” functions, which always deliver the same result for the same inputs. It is s for “stable” functions, whose results (for fixed inputs) do not change within a scan. It is v for “volatile” functions, whose results might change at any time. (Use v also for functions with side-effects, so that calls to them cannot get optimized away.)

proparallel

char

proparallel tells whether the function can be safely run in parallel mode. It is s for functions which are safe to run in parallel mode without restriction. It is r for functions which can be run in parallel mode, but their execution is restricted to the parallel group leader; parallel worker processes cannot invoke these functions. It is u for functions which are unsafe in parallel mode; the presence of such a function forces a serial execution plan.

pronargs

int2

Number of input arguments

pronargdefaults

int2

Number of arguments that have defaults

prorettype

oid

pg_type.oid

Data type of the return value

proargtypes

oidvector

pg_type.oid

An array with the data types of the function arguments. This includes only input arguments (including INOUT and VARIADIC arguments), and thus represents the call signature of the function.

proallargtypes

oid[]

pg_type.oid

An array with the data types of the function arguments. This includes all arguments (including OUT and INOUT arguments); however, if all the arguments are IN arguments, this field will be null. Note that subscripting is 1-based, whereas for historical reasons proargtypes is subscripted from 0.

proargmodes

char[]

An array with the modes of the function arguments, encoded as i for IN arguments, o for OUT arguments, b for INOUT arguments, v for VARIADIC arguments, t for TABLE arguments. If all the arguments are IN arguments, this field will be null. Note that subscripts correspond to positions of proallargtypes not proargtypes.

proargnames

text[]

An array with the names of the function arguments. Arguments without a name are set to empty strings in the array. If none of the arguments have a name, this field will be null. Note that subscripts correspond to positions of proallargtypes not proargtypes.

proargdefaults

pg_node_tree

Expression trees (in nodeToString() representation) for default values. This is a list with pronargdefaults elements, corresponding to the last N input arguments (i.e., the last N proargtypes positions). If none of the arguments have defaults, this field will be null.

protrftypes

oid[]

Data type OIDs for which to apply transforms.

prosrc

text

This tells the function handler how to invoke the function. It might be the actual source code of the function for interpreted languages, a link symbol, a file name, or just about anything else, depending on the implementation language/call convention.

probin

text

Additional information about how to invoke the function. Again, the interpretation is language-specific.

proconfig

text[]

Function's local settings for run-time configuration variables

proacl

aclitem[]

Access privileges; see Section 5.7 for details

對於內建和動態載入的已編譯函數,prosrc 包含函數的 C 語言名稱(link symbol)。對於所有其他目前已知的語言型別,prosrc 包含函數的原始碼。除了動態載入的 C 函數之外,probin 是未使用的,它為此提供了包含該函數的共享函式庫檔案的名稱。