mirror of
https://github.com/postgres/postgres.git
synced 2025-07-28 23:42:10 +03:00
Add width_bucket(anyelement, anyarray).
This provides a convenient method of classifying input values into buckets that are not necessarily equal-width. It works on any sortable data type. The choice of function name is a bit debatable, perhaps, but showing that there's a relationship to the SQL standard's width_bucket() function seems more attractive than the other proposals. Petr Jelinek, reviewed by Pavel Stehule
This commit is contained in:
Tom Lane
@ -1706,3 +1706,126 @@ select length(md5((f1[1]).c2)) from dest;
|
||||
|
||||
drop table dest;
|
||||
drop type textandtext;
|
||||
-- Tests for polymorphic-array form of width_bucket()
|
||||
-- this exercises the varwidth and float8 code paths
|
||||
SELECT
|
||||
op,
|
||||
width_bucket(op::numeric, ARRAY[1, 3, 5, 10.0]::numeric[]) AS wb_n1,
|
||||
width_bucket(op::numeric, ARRAY[0, 5.5, 9.99]::numeric[]) AS wb_n2,
|
||||
width_bucket(op::numeric, ARRAY[-6, -5, 2.0]::numeric[]) AS wb_n3,
|
||||
width_bucket(op::float8, ARRAY[1, 3, 5, 10.0]::float8[]) AS wb_f1,
|
||||
width_bucket(op::float8, ARRAY[0, 5.5, 9.99]::float8[]) AS wb_f2,
|
||||
width_bucket(op::float8, ARRAY[-6, -5, 2.0]::float8[]) AS wb_f3
|
||||
FROM (VALUES
|
||||
(-5.2),
|
||||
(-0.0000000001),
|
||||
(0.000000000001),
|
||||
(1),
|
||||
(1.99999999999999),
|
||||
(2),
|
||||
(2.00000000000001),
|
||||
(3),
|
||||
(4),
|
||||
(4.5),
|
||||
(5),
|
||||
(5.5),
|
||||
(6),
|
||||
(7),
|
||||
(8),
|
||||
(9),
|
||||
(9.99999999999999),
|
||||
(10),
|
||||
(10.0000000000001)
|
||||
) v(op);
|
||||
op | wb_n1 | wb_n2 | wb_n3 | wb_f1 | wb_f2 | wb_f3
|
||||
------------------+-------+-------+-------+-------+-------+-------
|
||||
-5.2 | 0 | 0 | 1 | 0 | 0 | 1
|
||||
-0.0000000001 | 0 | 0 | 2 | 0 | 0 | 2
|
||||
0.000000000001 | 0 | 1 | 2 | 0 | 1 | 2
|
||||
1 | 1 | 1 | 2 | 1 | 1 | 2
|
||||
1.99999999999999 | 1 | 1 | 2 | 1 | 1 | 2
|
||||
2 | 1 | 1 | 3 | 1 | 1 | 3
|
||||
2.00000000000001 | 1 | 1 | 3 | 1 | 1 | 3
|
||||
3 | 2 | 1 | 3 | 2 | 1 | 3
|
||||
4 | 2 | 1 | 3 | 2 | 1 | 3
|
||||
4.5 | 2 | 1 | 3 | 2 | 1 | 3
|
||||
5 | 3 | 1 | 3 | 3 | 1 | 3
|
||||
5.5 | 3 | 2 | 3 | 3 | 2 | 3
|
||||
6 | 3 | 2 | 3 | 3 | 2 | 3
|
||||
7 | 3 | 2 | 3 | 3 | 2 | 3
|
||||
8 | 3 | 2 | 3 | 3 | 2 | 3
|
||||
9 | 3 | 2 | 3 | 3 | 2 | 3
|
||||
9.99999999999999 | 3 | 3 | 3 | 3 | 3 | 3
|
||||
10 | 4 | 3 | 3 | 4 | 3 | 3
|
||||
10.0000000000001 | 4 | 3 | 3 | 4 | 3 | 3
|
||||
(19 rows)
|
||||
|
||||
-- ensure float8 path handles NaN properly
|
||||
SELECT
|
||||
op,
|
||||
width_bucket(op, ARRAY[1, 3, 9, 'NaN', 'NaN']::float8[]) AS wb
|
||||
FROM (VALUES
|
||||
(-5.2::float8),
|
||||
(4::float8),
|
||||
(77::float8),
|
||||
('NaN'::float8)
|
||||
) v(op);
|
||||
op | wb
|
||||
------+----
|
||||
-5.2 | 0
|
||||
4 | 2
|
||||
77 | 3
|
||||
NaN | 5
|
||||
(4 rows)
|
||||
|
||||
-- these exercise the generic fixed-width code path
|
||||
SELECT
|
||||
op,
|
||||
width_bucket(op, ARRAY[1, 3, 5, 10]) AS wb_1
|
||||
FROM generate_series(0,11) as op;
|
||||
op | wb_1
|
||||
----+------
|
||||
0 | 0
|
||||
1 | 1
|
||||
2 | 1
|
||||
3 | 2
|
||||
4 | 2
|
||||
5 | 3
|
||||
6 | 3
|
||||
7 | 3
|
||||
8 | 3
|
||||
9 | 3
|
||||
10 | 4
|
||||
11 | 4
|
||||
(12 rows)
|
||||
|
||||
SELECT width_bucket(now(),
|
||||
array['yesterday', 'today', 'tomorrow']::timestamptz[]);
|
||||
width_bucket
|
||||
--------------
|
||||
2
|
||||
(1 row)
|
||||
|
||||
-- corner cases
|
||||
SELECT width_bucket(5, ARRAY[3]);
|
||||
width_bucket
|
||||
--------------
|
||||
1
|
||||
(1 row)
|
||||
|
||||
SELECT width_bucket(5, '{}');
|
||||
width_bucket
|
||||
--------------
|
||||
0
|
||||
(1 row)
|
||||
|
||||
-- error cases
|
||||
SELECT width_bucket('5'::text, ARRAY[3, 4]::integer[]);
|
||||
ERROR: function width_bucket(text, integer[]) does not exist
|
||||
LINE 1: SELECT width_bucket('5'::text, ARRAY[3, 4]::integer[]);
|
||||
^
|
||||
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
|
||||
SELECT width_bucket(5, ARRAY[3, 4, NULL]);
|
||||
ERROR: thresholds array must not contain NULLs
|
||||
SELECT width_bucket(5, ARRAY[ARRAY[1, 2], ARRAY[3, 4]]);
|
||||
ERROR: thresholds must be one-dimensional array
|
||||
|
||||
@ -476,3 +476,65 @@ drop table src;
|
||||
select length(md5((f1[1]).c2)) from dest;
|
||||
drop table dest;
|
||||
drop type textandtext;
|
||||
|
||||
-- Tests for polymorphic-array form of width_bucket()
|
||||
|
||||
-- this exercises the varwidth and float8 code paths
|
||||
SELECT
|
||||
op,
|
||||
width_bucket(op::numeric, ARRAY[1, 3, 5, 10.0]::numeric[]) AS wb_n1,
|
||||
width_bucket(op::numeric, ARRAY[0, 5.5, 9.99]::numeric[]) AS wb_n2,
|
||||
width_bucket(op::numeric, ARRAY[-6, -5, 2.0]::numeric[]) AS wb_n3,
|
||||
width_bucket(op::float8, ARRAY[1, 3, 5, 10.0]::float8[]) AS wb_f1,
|
||||
width_bucket(op::float8, ARRAY[0, 5.5, 9.99]::float8[]) AS wb_f2,
|
||||
width_bucket(op::float8, ARRAY[-6, -5, 2.0]::float8[]) AS wb_f3
|
||||
FROM (VALUES
|
||||
(-5.2),
|
||||
(-0.0000000001),
|
||||
(0.000000000001),
|
||||
(1),
|
||||
(1.99999999999999),
|
||||
(2),
|
||||
(2.00000000000001),
|
||||
(3),
|
||||
(4),
|
||||
(4.5),
|
||||
(5),
|
||||
(5.5),
|
||||
(6),
|
||||
(7),
|
||||
(8),
|
||||
(9),
|
||||
(9.99999999999999),
|
||||
(10),
|
||||
(10.0000000000001)
|
||||
) v(op);
|
||||
|
||||
-- ensure float8 path handles NaN properly
|
||||
SELECT
|
||||
op,
|
||||
width_bucket(op, ARRAY[1, 3, 9, 'NaN', 'NaN']::float8[]) AS wb
|
||||
FROM (VALUES
|
||||
(-5.2::float8),
|
||||
(4::float8),
|
||||
(77::float8),
|
||||
('NaN'::float8)
|
||||
) v(op);
|
||||
|
||||
-- these exercise the generic fixed-width code path
|
||||
SELECT
|
||||
op,
|
||||
width_bucket(op, ARRAY[1, 3, 5, 10]) AS wb_1
|
||||
FROM generate_series(0,11) as op;
|
||||
|
||||
SELECT width_bucket(now(),
|
||||
array['yesterday', 'today', 'tomorrow']::timestamptz[]);
|
||||
|
||||
-- corner cases
|
||||
SELECT width_bucket(5, ARRAY[3]);
|
||||
SELECT width_bucket(5, '{}');
|
||||
|
||||
-- error cases
|
||||
SELECT width_bucket('5'::text, ARRAY[3, 4]::integer[]);
|
||||
SELECT width_bucket(5, ARRAY[3, 4, NULL]);
|
||||
SELECT width_bucket(5, ARRAY[ARRAY[1, 2], ARRAY[3, 4]]);
|
||||
|
||||
Reference in New Issue
Block a user