CREATE TABLE discard_unflushed_data_test (
    host STRING PRIMARY KEY,
    val DOUBLE,
    ts TIMESTAMP TIME INDEX
) ENGINE = mito;

Affected Rows: 0

INSERT INTO discard_unflushed_data_test VALUES ('persisted', 1, 1);

Affected Rows: 1

ADMIN FLUSH_TABLE('discard_unflushed_data_test');

+--------------------------------------------------+
| ADMIN FLUSH_TABLE('discard_unflushed_data_test') |
+--------------------------------------------------+
| 0                                                |
+--------------------------------------------------+

INSERT INTO discard_unflushed_data_test VALUES ('unflushed', 2, 2);

Affected Rows: 1

ADMIN discard_unflushed('discard_unflushed_data_test');

+--------------------------------------------------------+
| ADMIN discard_unflushed('discard_unflushed_data_test') |
+--------------------------------------------------------+
| 0                                                      |
+--------------------------------------------------------+

-- Repeating the operation is idempotent.
ADMIN discard_unflushed('discard_unflushed_data_test');

+--------------------------------------------------------+
| ADMIN discard_unflushed('discard_unflushed_data_test') |
+--------------------------------------------------------+
| 0                                                      |
+--------------------------------------------------------+

SELECT host, val FROM discard_unflushed_data_test ORDER BY host;

+-----------+-----+
| host      | val |
+-----------+-----+
| persisted | 1.0 |
+-----------+-----+

-- The function must only be available through ADMIN.
-- SQLNESS REPLACE \nDid\syou\smean.*
SELECT discard_unflushed(0);

Error: 3000(PlanQuery), Failed to plan SQL: Error during planning: Invalid function 'discard_unflushed'.

DROP TABLE discard_unflushed_data_test;

Affected Rows: 0

CREATE TABLE discard_unflushed_data_test (
    host STRING PRIMARY KEY,
    val DOUBLE,
    ts TIMESTAMP TIME INDEX
) ENGINE = mito;

Affected Rows: 0

INSERT INTO discard_unflushed_data_test VALUES ('unflushed', 1, 1);

Affected Rows: 1

-- The table has no persisted data, so discarding leaves it empty.
ADMIN discard_unflushed('discard_unflushed_data_test');

+--------------------------------------------------------+
| ADMIN discard_unflushed('discard_unflushed_data_test') |
+--------------------------------------------------------+
| 0                                                      |
+--------------------------------------------------------+

SELECT COUNT(*) FROM discard_unflushed_data_test;

+----------+
| count(*) |
+----------+
| 0        |
+----------+

DROP TABLE discard_unflushed_data_test;

Affected Rows: 0

CREATE TABLE discard_unflushed_data_physical (
    ts TIMESTAMP TIME INDEX,
    val DOUBLE
) ENGINE = metric WITH ("physical_metric_table" = "");

Affected Rows: 0

CREATE TABLE discard_unflushed_data_logical (
    host STRING PRIMARY KEY,
    val DOUBLE,
    ts TIMESTAMP TIME INDEX
) ENGINE = metric WITH ("on_physical_table" = "discard_unflushed_data_physical");

Affected Rows: 0

INSERT INTO discard_unflushed_data_logical VALUES ('unflushed', 1, 1);

Affected Rows: 1

-- Logical Metric Engine tables share their physical regions with other logical tables.
-- Discarding by logical table name must not truncate those shared regions.
ADMIN discard_unflushed('discard_unflushed_data_logical');

Error: 1002(Unexpected), Failed to execute admin function discard_unflushed: Execution error: Not supported: discarding unflushed data from a Metric Engine logical table

SELECT host, val FROM discard_unflushed_data_logical;

+-----------+-----+
| host      | val |
+-----------+-----+
| unflushed | 1.0 |
+-----------+-----+

DROP TABLE discard_unflushed_data_logical;

Affected Rows: 0

DROP TABLE discard_unflushed_data_physical;

Affected Rows: 0