fix: do not affect scalar function

Signed-off-by: yihong0618 <zouzou0208@gmail.com>

src/query/src/promql/planner.rs

@@ -409,6 +409,10 @@ impl PromPlanner {
                     }
                 }
                 let mut field_columns = left_field_columns.iter().zip(right_field_columns.iter());
+                let is_vector_matching = (left_field_columns.len() == 1
+                    && left_field_columns[0] == GREPTIME_VALUE)
+                    || (right_field_columns.len() == 1 && right_field_columns[0] == GREPTIME_VALUE);
+
                 let join_plan = self.join_on_non_field_columns(
                     left_input,
                     right_input,
@@ -417,6 +421,7 @@ impl PromPlanner {
                     // if left plan or right plan tag is empty, means case like `scalar(...) + host` or `host + scalar(...)`
                     // under this case we only join on time index
                     left_context.tag_columns.is_empty() || right_context.tag_columns.is_empty(),
+                    is_vector_matching,
                 )?;
                 let join_plan_schema = join_plan.schema().clone();
 
@@ -2003,6 +2008,7 @@ impl PromPlanner {
         left_table_ref: TableReference,
         right_table_ref: TableReference,
         only_join_time_index: bool,
+        is_vector_matching: bool,
     ) -> Result<LogicalPlan> {
         let mut tag_columns = if only_join_time_index {
             vec![]
@@ -2016,8 +2022,8 @@ impl PromPlanner {
 
         // push time index column if it exists
         if let Some(time_index_column) = &self.ctx.time_index_column {
-            // issue #5392 if only_join_time_index is true, we don't need to push time_index_column to tag_columns
-            if !only_join_time_index {
+            // issue #5392 if is special vector function
+            if !is_vector_matching {
                 tag_columns.push(Column::from_name(time_index_column));
             }
         }