pg_proc

The pg_proc system catalog table stores information about functions (or procedures), both built-in functions and those defined by CREATE FUNCTION. The table contains data for aggregate and window functions as well as plain functions. If proisagg is true, there should be a matching row in pg_aggregate.

For compiled functions, both built-in and dynamically loaded, prosrc contains the function’s C-language name (link symbol). For all other currently-known language types, prosrc contains the function’s source text. probin is unused except for dynamically-loaded C functions, for which it gives the name of the shared library file containing the function.

Table 1. pg_catalog.pg_proc

column	type	references	description
oid	oid		Row identifier (hidden attribute; must be explicitly selected).
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 cpu_operator_cost units); if proretset is true, identifies the 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	Planner support function for this function
prokind	char		f for a normal function, p for a procedure, a for an aggregate function, or w for a window function
prosecdef	boolean		Function is a security definer (for example, a ‘setuid’ function).
proleakproof	boolean		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	boolean		Function returns NULL if any call argument is NULL. In that case the function will not actually be called at all. Functions that are not strict must be prepared to handle NULL inputs.
proretset	boolean		Function returns a set (multiple values of the specified data type).
provolatile	char		Tells whether the function’s result depends only on its input arguments, or is affected by outside factors. i = immutable (always delivers the same result for the same inputs), s = stable (results (for fixed inputs) do not change within a scan), or v = volatile (results may change at any time or functions with side-effects).
proparallel	char		Indicates whether a function can be safely run in a parallel backend, or only in non-parallel mode
pronargs	smallint		Number of arguments.
pronargdefaults	smallint		Number of arguments that have default values.
prorettype	oid	pg_type.oid	Data type of the return value, or null for a procedure.
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 of 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: i = IN, o = OUT , b = INOUT, v = VARIADIC. 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 argument 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[]		Types 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 for the function as given by GRANT/REVOKE.
proexeclocation	char		Where the function runs when it is invoked: m - coordinator only, a - any segment instance, s - all segment instances, i - initplan.