postgresql/src/test/regress/sql/create_aggregate.sql
Tom Lane 24e2885ee3 Introduce "anycompatible" family of polymorphic types.
This patch adds the pseudo-types anycompatible, anycompatiblearray,
anycompatiblenonarray, and anycompatiblerange.  They work much like
anyelement, anyarray, anynonarray, and anyrange respectively, except
that the actual input values need not match precisely in type.
Instead, if we can find a common supertype (using the same rules
as for UNION/CASE type resolution), then the parser automatically
promotes the input values to that type.  For example,
"myfunc(anycompatible, anycompatible)" can match a call with one
integer and one bigint argument, with the integer automatically
promoted to bigint.  With anyelement in the definition, the user
would have had to cast the integer explicitly.

The new types also provide a second, independent set of type variables
for function matching; thus with "myfunc(anyelement, anyelement,
anycompatible) returns anycompatible" the first two arguments are
constrained to be the same type, but the third can be some other
type, and the result has the type of the third argument.  The need
for more than one set of type variables was foreseen back when we
first invented the polymorphic types, but we never did anything
about it.

Pavel Stehule, revised a bit by me

Discussion: https://postgr.es/m/CAFj8pRDna7VqNi8gR+Tt2Ktmz0cq5G93guc3Sbn_NVPLdXAkqA@mail.gmail.com
2020-03-19 11:43:11 -04:00

331 lines
8.1 KiB
PL/PgSQL

--
-- 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';
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';
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
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
create aggregate least_agg(int8) (
stype = int8, sfunc = least_accum
);
drop function least_accum(anycompatible, anycompatible) cascade;
-- 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_*
-- 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
);
-- serialfunc must have correct parameters
CREATE AGGREGATE myavg (numeric)
(
stype = internal,
sfunc = numeric_avg_accum,
serialfunc = numeric_avg_deserialize,
deserialfunc = numeric_avg_deserialize
);
-- deserialfunc must have correct parameters
CREATE AGGREGATE myavg (numeric)
(
stype = internal,
sfunc = numeric_avg_accum,
serialfunc = numeric_avg_serialize,
deserialfunc = numeric_avg_serialize
);
-- 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
);
-- 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;
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;
-- 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;
-- can't change return type:
CREATE OR REPLACE AGGREGATE myavg (numeric)
(
stype = numeric,
sfunc = numeric_add,
finalfunc = numeric_out
);
-- can't change to a different kind:
CREATE OR REPLACE AGGREGATE myavg (order by numeric)
(
stype = numeric,
sfunc = numeric_add
);
-- 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
);
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
);
-- 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
);
-- 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
);
-- invalid: non-lowercase quoted identifiers
CREATE AGGREGATE case_agg ( -- old syntax
"Sfunc1" = int4pl,
"Basetype" = int4,
"Stype1" = int4,
"Initcond1" = '0',
"Parallel" = safe
);
CREATE AGGREGATE case_agg(float8)
(
"Stype" = internal,
"Sfunc" = ordered_set_transition,
"Finalfunc" = percentile_disc_final,
"Finalfunc_extra" = true,
"Finalfunc_modify" = read_write,
"Parallel" = safe
);