pg_proc — PostgreSQL system catalog

The PostgreSQL pg_proc system catalog: full column reference (names, types, descriptions), catalog relationships and version support.

The Sev-1 Admin
The Sev-1 Admin  ·  5 min read

Summary

The catalog pg_proc stores information about functions, procedures, aggregate functions, and window functions (collectively also known as routines). See createfunction, createprocedure, and xfunc for more information.

(Description quoted from the official PostgreSQL documentation.)

Columns

The pg_proc system catalog exposes the following columns (names, types and descriptions are taken verbatim from the PostgreSQL documentation):

  • oid oid
    Row identifier
  • proname name
    Name of the function
  • pronamespace oid references pg_namespace.oid
    The OID of the namespace that contains this function
  • proowner oid references pg_authid.oid
    Owner of the function
  • prolang oid references 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 references 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 references pg_proc.oid
    Planner support function for this function (see xfunc_optimization), or zero if none
  • 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 leakproof.
  • 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 references pg_type.oid
    Data type of the return value
  • proargtypes oidvector references pg_type.oid
    An array of 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[] references pg_type.oid
    An array of 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 of 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 of 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[] references pg_type.oid
    An array of the argument/result data type(s) for which to apply transforms (from the function’s TRANSFORM clause). Null if none.
  • 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.
  • prosqlbody pg_node_tree
    Pre-parsed SQL function body. This is used for SQL-language functions when the body is given in SQL-standard notation rather than as a string literal. It’s null in other cases.
  • proconfig text[]
    Function’s local settings for run-time configuration variables
  • proacl aclitem[]
    Access privileges; see ddl_priv for details

Related catalogs

This object references the following other system catalogs:

Version applicability

Present in PostgreSQL 17, 18, 19 (verified against each release’s documentation). This is a long-standing system object that also exists in earlier PostgreSQL releases.

Related & references

Reference: PostgreSQL documentation — pg_proc.