fix: count(1) instead of count(ts) when >1 inputs (#6952)

Signed-off-by: discord9 <discord9@163.com>

src/query/src/optimizer/count_wildcard.rs

@@ -88,6 +88,10 @@ impl CountWildcardToTimeIndexRule {
         // check if the time index is a valid column as for current plan
         if let Some(col) = &col {
             let mut is_valid = false;
+            // if more than one input, we give up and just use `count(1)`
+            if plan.inputs().len() > 1 {
+                return None;
+            }
             for input in plan.inputs() {
                 if input.schema().has_column(col) {
                     is_valid = true;
@@ -168,6 +172,11 @@ impl TreeNodeVisitor<'_> for TimeIndexFinder {
             return Ok(TreeNodeRecursion::Stop);
         }
 
+        if node.inputs().len() > 1 {
+            // if more than one input, we give up and just use `count(1)`
+            return Ok(TreeNodeRecursion::Stop);
+        }
+
         Ok(TreeNodeRecursion::Continue)
     }