Files
greptimedb/tests/compatibility/cases/stddev_pop_state/setup.sql
T
Lei, HUANG c6b10bfbb9 feat(function): add mergeable stddev_pop state functions (#8972)
* feat(function): add Welford stddev functions

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* test(function): cover merged Welford time windows

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* refactor(function): use stddev_pop SQL names

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* fix(function): make Welford arithmetic partition-stable

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* fix(function): reject invalid singleton Welford states

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* test(function): pin Welford state compatibility

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* refactor(function): remove unreachable variance clamp

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* fix(function): reject DISTINCT Welford aggregates

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

* test(compat): bound Welford downgrade targets

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>

---------

Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>
2026-08-31 14:15:33 +00:00

27 lines
528 B
SQL

CREATE TABLE stddev_values (
seq_id INT PRIMARY KEY,
grp INT,
val DOUBLE,
ts TIMESTAMP TIME INDEX DEFAULT now()
);
INSERT INTO stddev_values (seq_id, grp, val) VALUES
(1, 0, 1.0),
(2, 0, 2.0),
(3, 1, 3.0),
(4, 1, 4.0);
CREATE TABLE stddev_states (
grp INT PRIMARY KEY,
state BINARY,
ts TIMESTAMP TIME INDEX DEFAULT now()
);
INSERT INTO stddev_states (grp, state)
SELECT grp, stddev_pop_state(val)
FROM stddev_values
GROUP BY grp;
ADMIN FLUSH_TABLE('stddev_values');
ADMIN FLUSH_TABLE('stddev_states');