51.39. pg_proc

The catalog pg_proc stores information about functions, procedures, aggregate functions, and window functions (collectively also known as routines). See CREATE FUNCTION, CREATE PROCEDURE, and Section 37.3 for more information.

If prokind indicates that the entry is for an aggregate function, there should be a matching row in pg_aggregate.

Table 51.39. pg_proc Columns

NameTypeReferencesDescription
oidoid Row identifier (hidden attribute; must be explicitly selected)
pronamename Name of the function
pronamespaceoidpg_namespace.oid The OID of the namespace that contains this function
proowneroidpg_authid.oidOwner of the function
prolangoidpg_language.oidImplementation language or call interface of this function
procostfloat4 Estimated execution cost (in units of cpu_operator_cost); if proretset, this is cost per row returned
prorowsfloat4 Estimated number of result rows (zero if not proretset)
provariadicoidpg_type.oidData type of the variadic array parameter's elements, or zero if the function does not have a variadic parameter
protransformregprocpg_proc.oidCalls to this function can be simplified by this other function (see Section 37.10.10)
prokindchar f for a normal function, p for a procedure, a for an aggregate function, or w for a window function
prosecdefbool Function is a security definer (i.e., a setuid function)
proleakproofbool  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.
proisstrictbool  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.
proretsetbool Function returns a set (i.e., multiple values of the specified data type)
provolatilechar 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.)
proparallelchar 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.
pronargsint2 Number of input arguments
pronargdefaultsint2 Number of arguments that have defaults
prorettypeoidpg_type.oidData type of the return value
proargtypesoidvectorpg_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.
proallargtypesoid[]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.
proargmodeschar[]  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.
proargnamestext[]  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.
proargdefaultspg_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.
protrftypesoid[]  Data type OIDs for which to apply transforms.
prosrctext  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.
probintext  Additional information about how to invoke the function. Again, the interpretation is language-specific.
proconfigtext[] Function's local settings for run-time configuration variables
proaclaclitem[]  Access privileges; see GRANT and REVOKE for details

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.