DESC TABLE information_schema.table_semantics;

+------------------+--------+-----+------+---------+---------------+
| Column           | Type   | Key | Null | Default | Semantic Type |
+------------------+--------+-----+------+---------+---------------+
| table_catalog    | String |     | NO   |         | FIELD         |
| table_schema     | String |     | NO   |         | FIELD         |
| table_name       | String |     | NO   |         | FIELD         |
| table_id         | UInt32 |     | NO   |         | FIELD         |
| signal_type      | String |     | YES  |         | FIELD         |
| source           | String |     | YES  |         | FIELD         |
| source_version   | String |     | YES  |         | FIELD         |
| pipeline         | String |     | YES  |         | FIELD         |
| metadata_quality | String |     | YES  |         | FIELD         |
| semantic_options | String |     | YES  |         | FIELD         |
+------------------+--------+-----+------+---------+---------------+

CREATE TABLE metrics_tagged (
  ts TIMESTAMP TIME INDEX,
  val DOUBLE,
)
WITH (
  'greptime.semantic.signal_type' = 'metric',
  'greptime.semantic.source' = 'opentelemetry',
  'greptime.semantic.source_version' = '2.0',
  'greptime.semantic.pipeline' = 'greptime_metric_v1',
  'greptime.semantic.metric.metadata_quality' = 'declared',
  'greptime.semantic.metric.type' = 'counter',
  'greptime.semantic.metric.unit' = 'By'
);

Affected Rows: 0

CREATE TABLE traces_tagged (
  ts TIMESTAMP TIME INDEX,
  span_name STRING,
)
WITH (
  'greptime.semantic.signal_type' = 'trace',
  'greptime.semantic.source' = 'opentelemetry',
  'greptime.semantic.trace.conventions' = 'https://opentelemetry.io/schemas/1.27.0'
);

Affected Rows: 0

-- A table with no semantic options must not appear in the view.
CREATE TABLE plain_table (
  ts TIMESTAMP TIME INDEX,
  val DOUBLE,
);

Affected Rows: 0

SELECT table_schema, table_name, signal_type, source, source_version, pipeline, metadata_quality, semantic_options
FROM information_schema.table_semantics
ORDER BY table_name;

+--------------+----------------+-------------+---------------+----------------+--------------------+------------------+-----------------------------------------------------------------+
| table_schema | table_name     | signal_type | source        | source_version | pipeline           | metadata_quality | semantic_options                                                |
+--------------+----------------+-------------+---------------+----------------+--------------------+------------------+-----------------------------------------------------------------+
| public       | metrics_tagged | metric      | opentelemetry | 2.0            | greptime_metric_v1 | declared         | {"metric.type":"counter","metric.unit":"By"}                    |
| public       | traces_tagged  | trace       | opentelemetry |                |                    |                  | {"trace.conventions":"https://opentelemetry.io/schemas/1.27.0"} |
+--------------+----------------+-------------+---------------+----------------+--------------------+------------------+-----------------------------------------------------------------+

-- Predicate pushdown on a promoted column.
SELECT table_name, signal_type
FROM information_schema.table_semantics
WHERE signal_type = 'metric'
ORDER BY table_name;

+----------------+-------------+
| table_name     | signal_type |
+----------------+-------------+
| metrics_tagged | metric      |
+----------------+-------------+

DROP TABLE metrics_tagged;

Affected Rows: 0

DROP TABLE traces_tagged;

Affected Rows: 0

DROP TABLE plain_table;

Affected Rows: 0