docs: SHOW FLOW & FLOWS table info

docs/nightly/en/reference/sql/information-schema/flows.md

@@ -0,0 +1,32 @@
+# FLOWS
+The Flows table provide the flow task's information.
+
+```sql
+public=> DESC TABLE INFORMATION_SCHEMA.FLOWS;
+      Column      |  Type  | Key | Null | Default | Semantic Type 
+------------------+--------+-----+------+---------+---------------
+ flow_name        | String |     | NO   |         | FIELD
+ flow_id          | UInt32 |     | NO   |         | FIELD
+ table_catalog    | String |     | NO   |         | FIELD
+ flow_definition  | String |     | NO   |         | FIELD
+ comment          | String |     | YES  |         | FIELD
+ expire_after     | Int64  |     | YES  |         | FIELD
+ source_table_ids | String |     | YES  |         | FIELD
+ sink_table_name  | String |     | NO   |         | FIELD
+ flownode_ids     | String |     | YES  |         | FIELD
+ options          | String |     | YES  |         | FIELD
+(10 rows)
+```
+
+The columns in table:
+
+* `flow_name`: the flow task's name.
+* `flow_id`: the flow task's id.
+* `table_catalog`: the catalog this flow belongs to, named as `table_catalog` to keep consistent with the `INFORMATION_SCHEMA` standard.
+* `flow_definition`: the flow task's definition. It's the SQL statement that were used to creates the flow task.
+* `comment`: the comment of the flow task.
+* `expire_after`: the expire time of the flow task.
+* `source_table_ids`: the source table ids of the flow task.
+* `sink_table_name`: the sink table name of the flow task.
+* `flownode_ids`: the flownode ids used by the flow task.
+* `options`: extra options of the flow task.

docs/nightly/en/reference/sql/information-schema/overview.md

@@ -54,6 +54,7 @@ There is still lots of work to do for `INFORMATION_SCHEMA`. The tracking [issue]
 | [`REGION_PEERS`](./region-peers.md) | Provides details about where regions are stored. |
 | [`RUNTIME_METRICS`](./runtime-metrics.md)| Provides the system runtime metrics.|
 | [`CLUSTER_INFO`](./cluster-info.md)| Provides the topology information of the cluster.|
+| [`FLOWS`](./flows.md) | Provides the flow information.|
 
 
 

docs/nightly/en/reference/sql/show.md

@@ -176,3 +176,39 @@ WITH(
 
 * `Table`: the table name.
 * `Create Table`: The SQL to create the table.
+
+## SHOW CREATE FLOW
+
+Shows the `CREATE FLOW` statement that creates the flow task.
+
+For example:
+
+```sql
+public=> SHOW CREATE FLOW filter_numbers;
+      Flow      |                      Create Flow                      
+----------------+-------------------------------------------------------
+ filter_numbers | CREATE OR REPLACE FLOW IF NOT EXISTS filter_numbers  +
+                | SINK TO out_num_cnt                                  +
+                | AS SELECT number FROM numbers_input WHERE number > 10
+(1 row)
+```
+
+## SHOW FLOWS
+
+Show all flows:
+
+```sql
+public=> SHOW FLOWS;
+     Flows      
+----------------
+ filter_numbers
+(1 row)
+```
+also support `LIKE` expression:
+``sql
+public=> show flows like "filter%";
+     Flows      
+----------------
+ filter_numbers
+(1 row)
+```