ALTER AGGREGATE — change the definition of an aggregate function
ALTER AGGREGATEname(aggregate_signature) RENAME TOnew_nameALTER AGGREGATEname(aggregate_signature) OWNER TO {new_owner| CURRENT_USER | SESSION_USER } ALTER AGGREGATEname(aggregate_signature) SET SCHEMAnew_schemawhereaggregate_signatureis: * | [argmode] [argname]argtype[ , ... ] | [ [argmode] [argname]argtype[ , ... ] ] ORDER BY [argmode] [argname]argtype[ , ... ]
   ALTER AGGREGATE changes the definition of an
   aggregate function.
  
   You must own the aggregate function to use ALTER AGGREGATE.
   To change the schema of an aggregate function, you must also have
   CREATE privilege on the new schema.
   To alter the owner, you must also be a direct or indirect member of the new
   owning role, and that role must have CREATE privilege on
   the aggregate function's schema.  (These restrictions enforce that altering
   the owner doesn't do anything you couldn't do by dropping and recreating
   the aggregate function.  However, a superuser can alter ownership of any
   aggregate function anyway.)
  
nameThe name (optionally schema-qualified) of an existing aggregate function.
argmode      The mode of an argument: IN or VARIADIC.
      If omitted, the default is IN.
     
argname      The name of an argument.
      Note that ALTER AGGREGATE does not actually pay
      any attention to argument names, since only the argument data
      types are needed to determine the aggregate function's identity.
     
argtype      An input data type on which the aggregate function operates.
      To reference a zero-argument aggregate function, write *
      in place of the list of argument specifications.
      To reference an ordered-set aggregate function, write
      ORDER BY between the direct and aggregated argument
      specifications.
     
new_nameThe new name of the aggregate function.
new_ownerThe new owner of the aggregate function.
new_schemaThe new schema for the aggregate function.
    The recommended syntax for referencing an ordered-set aggregate
    is to write ORDER BY between the direct and aggregated
    argument specifications, in the same style as in
    CREATE AGGREGATE.  However, it will also work to
    omit ORDER BY and just run the direct and aggregated
    argument specifications into a single list.  In this abbreviated form,
    if VARIADIC "any" was used in both the direct and
    aggregated argument lists, write VARIADIC "any" only once.
   
   To rename the aggregate function myavg for type
   integer to my_average:
ALTER AGGREGATE myavg(integer) RENAME TO my_average;
   To change the owner of the aggregate function myavg for type
   integer to joe:
ALTER AGGREGATE myavg(integer) OWNER TO joe;
   To move the ordered-set aggregate mypercentile with
   direct argument of type float8 and aggregated argument
   of type integer into schema myschema:
ALTER AGGREGATE mypercentile(float8 ORDER BY integer) SET SCHEMA myschema;
This will work too:
ALTER AGGREGATE mypercentile(float8, integer) SET SCHEMA myschema;
   There is no ALTER AGGREGATE statement in the SQL
   standard.