--
-- CREATE_AGGREGATE
--
-- all functions CREATEd
CREATE AGGREGATE newavg (
   sfunc = int4_avg_accum, basetype = int4, stype = _int8,
   finalfunc = int8_avg,
   initcond1 = '{0,0}'
);
-- test comments
COMMENT ON AGGREGATE newavg_wrong (int4) IS 'an agg comment';
ERROR:  aggregate newavg_wrong(integer) does not exist
COMMENT ON AGGREGATE newavg (int4) IS 'an agg comment';
COMMENT ON AGGREGATE newavg (int4) IS NULL;
-- without finalfunc; test obsolete spellings 'sfunc1' etc
CREATE AGGREGATE newsum (
   sfunc1 = int4pl, basetype = int4, stype1 = int4,
   initcond1 = '0'
);
-- zero-argument aggregate
CREATE AGGREGATE newcnt (*) (
   sfunc = int8inc, stype = int8,
   initcond = '0', parallel = safe
);
-- old-style spelling of same (except without parallel-safe; that's too new)
CREATE AGGREGATE oldcnt (
   sfunc = int8inc, basetype = 'ANY', stype = int8,
   initcond = '0'
);
-- aggregate that only cares about null/nonnull input
CREATE AGGREGATE newcnt ("any") (
   sfunc = int8inc_any, stype = int8,
   initcond = '0'
);
COMMENT ON AGGREGATE nosuchagg (*) IS 'should fail';
ERROR:  aggregate nosuchagg(*) does not exist
COMMENT ON AGGREGATE newcnt (*) IS 'an agg(*) comment';
COMMENT ON AGGREGATE newcnt ("any") IS 'an agg(any) comment';
-- multi-argument aggregate
create function sum3(int8,int8,int8) returns int8 as
'select $1 + $2 + $3' language sql strict immutable;
create aggregate sum2(int8,int8) (
   sfunc = sum3, stype = int8,
   initcond = '0'
);
-- multi-argument aggregates sensitive to distinct/order, strict/nonstrict
create type aggtype as (a integer, b integer, c text);
create function aggf_trans(aggtype[],integer,integer,text) returns aggtype[]
as 'select array_append($1,ROW($2,$3,$4)::aggtype)'
language sql strict immutable;
create function aggfns_trans(aggtype[],integer,integer,text) returns aggtype[]
as 'select array_append($1,ROW($2,$3,$4)::aggtype)'
language sql immutable;
create aggregate aggfstr(integer,integer,text) (
   sfunc = aggf_trans, stype = aggtype[],
   initcond = '{}'
);
create aggregate aggfns(integer,integer,text) (
   sfunc = aggfns_trans, stype = aggtype[], sspace = 10000,
   initcond = '{}'
);
-- check error cases that would require run-time type coercion
create function least_accum(int8, int8) returns int8 language sql as
  'select least($1, $2)';
create aggregate least_agg(int4) (
  stype = int8, sfunc = least_accum
);  -- fails
ERROR:  function least_accum(bigint, bigint) requires run-time type coercion
drop function least_accum(int8, int8);
create function least_accum(anycompatible, anycompatible)
returns anycompatible language sql as
  'select least($1, $2)';
create aggregate least_agg(int4) (
  stype = int8, sfunc = least_accum
);  -- fails
ERROR:  function least_accum(bigint, bigint) requires run-time type coercion
create aggregate least_agg(int8) (
  stype = int8, sfunc = least_accum
);
drop function least_accum(anycompatible, anycompatible) cascade;
NOTICE:  drop cascades to function least_agg(bigint)
-- variadic aggregates
create function least_accum(anyelement, variadic anyarray)
returns anyelement language sql as
  'select least($1, min($2[i])) from generate_subscripts($2,1) g(i)';
create aggregate least_agg(variadic items anyarray) (
  stype = anyelement, sfunc = least_accum
);
create function cleast_accum(anycompatible, variadic anycompatiblearray)
returns anycompatible language sql as
  'select least($1, min($2[i])) from generate_subscripts($2,1) g(i)';
create aggregate cleast_agg(variadic items anycompatiblearray) (
  stype = anycompatible, sfunc = cleast_accum
);
-- test ordered-set aggs using built-in support functions
create aggregate my_percentile_disc(float8 ORDER BY anyelement) (
  stype = internal,
  sfunc = ordered_set_transition,
  finalfunc = percentile_disc_final,
  finalfunc_extra = true,
  finalfunc_modify = read_write
);
create aggregate my_rank(VARIADIC "any" ORDER BY VARIADIC "any") (
  stype = internal,
  sfunc = ordered_set_transition_multi,
  finalfunc = rank_final,
  finalfunc_extra = true,
  hypothetical
);
alter aggregate my_percentile_disc(float8 ORDER BY anyelement)
  rename to test_percentile_disc;
alter aggregate my_rank(VARIADIC "any" ORDER BY VARIADIC "any")
  rename to test_rank;
\da test_*
                                       List of aggregate functions
 Schema |         Name         | Result data type |          Argument data types           | Description 
--------+----------------------+------------------+----------------------------------------+-------------
 public | test_percentile_disc | anyelement       | double precision ORDER BY anyelement   | 
 public | test_rank            | bigint           | VARIADIC "any" ORDER BY VARIADIC "any" | 
(2 rows)

-- moving-aggregate options
CREATE AGGREGATE sumdouble (float8)
(
    stype = float8,
    sfunc = float8pl,
    mstype = float8,
    msfunc = float8pl,
    minvfunc = float8mi
);
-- aggregate combine and serialization functions
-- can't specify just one of serialfunc and deserialfunc
CREATE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	serialfunc = numeric_avg_serialize
);
ERROR:  must specify both or neither of serialization and deserialization functions
-- serialfunc must have correct parameters
CREATE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	serialfunc = numeric_avg_deserialize,
	deserialfunc = numeric_avg_deserialize
);
ERROR:  function numeric_avg_deserialize(internal) does not exist
-- deserialfunc must have correct parameters
CREATE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	serialfunc = numeric_avg_serialize,
	deserialfunc = numeric_avg_serialize
);
ERROR:  function numeric_avg_serialize(bytea, internal) does not exist
-- ensure combine function parameters are checked
CREATE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	serialfunc = numeric_avg_serialize,
	deserialfunc = numeric_avg_deserialize,
	combinefunc = int4larger
);
ERROR:  function int4larger(internal, internal) does not exist
-- ensure create aggregate works.
CREATE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	finalfunc = numeric_avg,
	serialfunc = numeric_avg_serialize,
	deserialfunc = numeric_avg_deserialize,
	combinefunc = numeric_avg_combine,
	finalfunc_modify = shareable  -- just to test a non-default setting
);
-- Ensure all these functions made it into the catalog
SELECT aggfnoid, aggtransfn, aggcombinefn, aggtranstype::regtype,
       aggserialfn, aggdeserialfn, aggfinalmodify
FROM pg_aggregate
WHERE aggfnoid = 'myavg'::REGPROC;
 aggfnoid |    aggtransfn     |    aggcombinefn     | aggtranstype |      aggserialfn      |      aggdeserialfn      | aggfinalmodify 
----------+-------------------+---------------------+--------------+-----------------------+-------------------------+----------------
 myavg    | numeric_avg_accum | numeric_avg_combine | internal     | numeric_avg_serialize | numeric_avg_deserialize | s
(1 row)

DROP AGGREGATE myavg (numeric);
-- create or replace aggregate
CREATE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	finalfunc = numeric_avg
);
CREATE OR REPLACE AGGREGATE myavg (numeric)
(
	stype = internal,
	sfunc = numeric_avg_accum,
	finalfunc = numeric_avg,
	serialfunc = numeric_avg_serialize,
	deserialfunc = numeric_avg_deserialize,
	combinefunc = numeric_avg_combine,
	finalfunc_modify = shareable  -- just to test a non-default setting
);
-- Ensure all these functions made it into the catalog again
SELECT aggfnoid, aggtransfn, aggcombinefn, aggtranstype::regtype,
       aggserialfn, aggdeserialfn, aggfinalmodify
FROM pg_aggregate
WHERE aggfnoid = 'myavg'::REGPROC;
 aggfnoid |    aggtransfn     |    aggcombinefn     | aggtranstype |      aggserialfn      |      aggdeserialfn      | aggfinalmodify 
----------+-------------------+---------------------+--------------+-----------------------+-------------------------+----------------
 myavg    | numeric_avg_accum | numeric_avg_combine | internal     | numeric_avg_serialize | numeric_avg_deserialize | s
(1 row)

-- can change stype:
CREATE OR REPLACE AGGREGATE myavg (numeric)
(
	stype = numeric,
	sfunc = numeric_add
);
SELECT aggfnoid, aggtransfn, aggcombinefn, aggtranstype::regtype,
       aggserialfn, aggdeserialfn, aggfinalmodify
FROM pg_aggregate
WHERE aggfnoid = 'myavg'::REGPROC;
 aggfnoid | aggtransfn  | aggcombinefn | aggtranstype | aggserialfn | aggdeserialfn | aggfinalmodify 
----------+-------------+--------------+--------------+-------------+---------------+----------------
 myavg    | numeric_add | -            | numeric      | -           | -             | r
(1 row)

-- can't change return type:
CREATE OR REPLACE AGGREGATE myavg (numeric)
(
	stype = numeric,
	sfunc = numeric_add,
	finalfunc = numeric_out
);
ERROR:  cannot change return type of existing function
HINT:  Use DROP AGGREGATE myavg(numeric) first.
-- can't change to a different kind:
CREATE OR REPLACE AGGREGATE myavg (order by numeric)
(
	stype = numeric,
	sfunc = numeric_add
);
ERROR:  cannot change routine kind
DETAIL:  "myavg" is an ordinary aggregate function.
-- can't change plain function to aggregate:
create function sum4(int8,int8,int8,int8) returns int8 as
'select $1 + $2 + $3 + $4' language sql strict immutable;
CREATE OR REPLACE AGGREGATE sum3 (int8,int8,int8)
(
	stype = int8,
	sfunc = sum4
);
ERROR:  cannot change routine kind
DETAIL:  "sum3" is a function.
drop function sum4(int8,int8,int8,int8);
DROP AGGREGATE myavg (numeric);
-- invalid: bad parallel-safety marking
CREATE AGGREGATE mysum (int)
(
	stype = int,
	sfunc = int4pl,
	parallel = pear
);
ERROR:  parameter "parallel" must be SAFE, RESTRICTED, or UNSAFE
-- invalid: nonstrict inverse with strict forward function
CREATE FUNCTION float8mi_n(float8, float8) RETURNS float8 AS
$$ SELECT $1 - $2; $$
LANGUAGE SQL;
CREATE AGGREGATE invalidsumdouble (float8)
(
    stype = float8,
    sfunc = float8pl,
    mstype = float8,
    msfunc = float8pl,
    minvfunc = float8mi_n
);
ERROR:  strictness of aggregate's forward and inverse transition functions must match
-- invalid: non-matching result types
CREATE FUNCTION float8mi_int(float8, float8) RETURNS int AS
$$ SELECT CAST($1 - $2 AS INT); $$
LANGUAGE SQL;
CREATE AGGREGATE wrongreturntype (float8)
(
    stype = float8,
    sfunc = float8pl,
    mstype = float8,
    msfunc = float8pl,
    minvfunc = float8mi_int
);
ERROR:  return type of inverse transition function float8mi_int is not double precision
-- invalid: non-lowercase quoted identifiers
CREATE AGGREGATE case_agg ( -- old syntax
	"Sfunc1" = int4pl,
	"Basetype" = int4,
	"Stype1" = int4,
	"Initcond1" = '0',
	"Parallel" = safe
);
WARNING:  aggregate attribute "Sfunc1" not recognized
WARNING:  aggregate attribute "Basetype" not recognized
WARNING:  aggregate attribute "Stype1" not recognized
WARNING:  aggregate attribute "Initcond1" not recognized
WARNING:  aggregate attribute "Parallel" not recognized
ERROR:  aggregate stype must be specified
CREATE AGGREGATE case_agg(float8)
(
	"Stype" = internal,
	"Sfunc" = ordered_set_transition,
	"Finalfunc" = percentile_disc_final,
	"Finalfunc_extra" = true,
	"Finalfunc_modify" = read_write,
	"Parallel" = safe
);
WARNING:  aggregate attribute "Stype" not recognized
WARNING:  aggregate attribute "Sfunc" not recognized
WARNING:  aggregate attribute "Finalfunc" not recognized
WARNING:  aggregate attribute "Finalfunc_extra" not recognized
WARNING:  aggregate attribute "Finalfunc_modify" not recognized
WARNING:  aggregate attribute "Parallel" not recognized
ERROR:  aggregate stype must be specified