CREATE TABLE test_hll (
    `id` INT PRIMARY KEY,
    `value` STRING,
    `ts` timestamp time index default now()
);

Affected Rows: 0

INSERT INTO test_hll (`id`, `value`) VALUES
    (1, "a"),
    (2, "b"),
    (5, "e"),
    (6, "f"),
    (7, "g"),
    (8, "h"),
    (9, "i"),
    (10, "j"),
    (11, "i"),
    (12, "j"),
    (13, "i"),
    (14, "n"),
    (15, "o");

Affected Rows: 13

select hll_count(hll(`value`)) from test_hll;

+--------------------------------+
| hll_count(hll(test_hll.value)) |
+--------------------------------+
| 10                             |
+--------------------------------+

INSERT INTO test_hll (`id`, `value`) VALUES
    (16, "b"),
    (17, "i"),
    (18, "j"),
    (19, "s"),
    (20, "t");

Affected Rows: 5

select hll_count(hll(`value`)) from test_hll;

+--------------------------------+
| hll_count(hll(test_hll.value)) |
+--------------------------------+
| 12                             |
+--------------------------------+

create table test_hll_merge (
    `id` INT PRIMARY KEY,
    `state` BINARY,
    `ts` timestamp time index default now()
);

Affected Rows: 0

insert into test_hll_merge (`id`, `state`)
select 1, hll(`value`) from test_hll;

Affected Rows: 1

insert into test_hll_merge (`id`, `state`)
select 2, hll(`value`) from test_hll;

Affected Rows: 1

select hll_count(hll_merge(`state`)) from test_hll_merge;

+--------------------------------------------+
| hll_count(hll_merge(test_hll_merge.state)) |
+--------------------------------------------+
| 12                                         |
+--------------------------------------------+

drop table test_hll;

Affected Rows: 0

drop table test_hll_merge;

Affected Rows: 0