fix(expr): cast untyped start and step when inferring type for `g…

…enerate_series` (#18786)

Signed-off-by: Richard Chien <[email protected]>

e2e_test/batch/basic/generate_series.slt.part

@@ -148,3 +148,22 @@ SELECT * FROM generate_series(0::numeric,10::numeric,'nan'::numeric);
 
 statement error start value cannot be infinity
 SELECT * FROM generate_series('-infinity'::numeric,'infinity'::numeric,'nan'::numeric);
+
+# ------
+# generate_series(timestamptz, timestamptz, interval) is not supported in batch mode
+
+statement error Unsupported function
+select * from generate_series(
+  '2024-06-21 17:36:00'::timestamptz,
+  now(),
+  interval '1 hour'
+);
+
+statement error Unsupported function
+select * from generate_series(
+  '2024-06-21 17:36:00',
+  now(),
+  '1 hour'
+);
+
+# ------

src/frontend/planner_test/tests/testdata/input/generate_series_with_now.yaml

@@ -8,6 +8,16 @@
     - logical_plan
     - optimized_logical_plan_for_stream
     - stream_plan
+- sql: |
+    select * from generate_series(
+      '2024-06-21 17:36:00',
+      now(),
+      '1 hour'
+    );
+  expected_outputs:
+    - logical_plan
+    - optimized_logical_plan_for_stream
+    - stream_plan
 - sql: |
     select * from generate_series(
       '2024-06-21 17:36:00'::timestamp, -- `timestamp` type is not supported

src/frontend/planner_test/tests/testdata/output/generate_series_with_now.yaml

@@ -12,6 +12,19 @@
   stream_plan: |-
     StreamMaterialize { columns: [generate_series], stream_key: [generate_series], pk_columns: [generate_series], pk_conflict: NoCheck, watermark_columns: [generate_series] }
     └─StreamNow { output: [ts] }
+- sql: |
+    select * from generate_series(
+      '2024-06-21 17:36:00',
+      now(),
+      '1 hour'
+    );
+  logical_plan: |-
+    LogicalProject { exprs: [generate_series] }
+    └─LogicalTableFunction { table_function: GenerateSeries('2024-06-21 17:36:00':Varchar::Timestamptz, Now, '01:00:00':Interval) }
+  optimized_logical_plan_for_stream: 'LogicalNow { output: [ts] }'
+  stream_plan: |-
+    StreamMaterialize { columns: [generate_series], stream_key: [generate_series], pk_columns: [generate_series], pk_conflict: NoCheck, watermark_columns: [generate_series] }
+    └─StreamNow { output: [ts] }
 - sql: |
     select * from generate_series(
       '2024-06-21 17:36:00'::timestamp, -- `timestamp` type is not supported

src/frontend/src/expr/type_inference/func.rs

@@ -704,10 +704,18 @@ fn infer_type_for_special_table_function(
 ) -> Result<Option<DataType>> {
     match func_type {
         PbTableFuncType::GenerateSeries => {
-            if inputs.len() < 3 {
+            if inputs.len() < 3 || !inputs[1].is_now() {
                 // let signature map handle this
                 return Ok(None);
             }
+            // Now we are inferring type for `generate_series(start, now(), step)`, which will
+            // be further handled by `GenerateSeriesWithNowRule`.
+            if inputs[0].is_untyped() {
+                inputs[0].cast_implicit_mut(DataType::Timestamptz)?;
+            }
+            if inputs[2].is_untyped() {
+                inputs[2].cast_implicit_mut(DataType::Interval)?;
+            }
             match (
                 inputs[0].return_type(),
                 inputs[1].return_type(),