From 89c8c31fa81a9a96a43452b32ef8936bee1adae4 Mon Sep 17 00:00:00 2001
From: HappenLee <happenlee@hotmail.com>
Date: Wed, 17 Apr 2024 22:26:32 +0800
Subject: [PATCH 1/2] [exec](table_fun) opt numbers table func performance

---
 .../exprs/table_function/vexplode_numbers.h   | 30 ++++++++++++-------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/be/src/vec/exprs/table_function/vexplode_numbers.h b/be/src/vec/exprs/table_function/vexplode_numbers.h
index 211565ec8b4f77..a60feba1adc5ab 100644
--- a/be/src/vec/exprs/table_function/vexplode_numbers.h
+++ b/be/src/vec/exprs/table_function/vexplode_numbers.h
@@ -28,11 +28,9 @@
 #include "vec/data_types/data_type.h"
 #include "vec/exprs/table_function/table_function.h"
 
-namespace doris {
-namespace vectorized {
+namespace doris::vectorized {
 class Block;
-} // namespace vectorized
-} // namespace doris
+} // namespace doris::vectorized
 
 namespace doris::vectorized {
 
@@ -48,8 +46,8 @@ class VExplodeNumbersTableFunction : public TableFunction {
     void process_close() override;
     void get_value(MutableColumnPtr& column) override;
     int get_value(MutableColumnPtr& column, int max_step) override {
+        max_step = std::min(max_step, (int)(_cur_size - _cur_offset));
         if (_is_const) {
-            max_step = std::min(max_step, (int)(_cur_size - _cur_offset));
             if (_is_nullable) {
                 static_cast<ColumnInt32*>(
                         static_cast<ColumnNullable*>(column.get())->get_nested_column_ptr().get())
@@ -61,12 +59,24 @@ class VExplodeNumbersTableFunction : public TableFunction {
                 static_cast<ColumnInt32*>(column.get())
                         ->insert_range_from(*_elements_column, _cur_offset, max_step);
             }
-
-            forward(max_step);
-            return max_step;
+        } else {
+            ColumnInt32* target = nullptr;
+            if (_is_nullable) {
+                target = assert_cast<ColumnInt32*>(
+                        assert_cast<ColumnNullable*>(column.get())->get_nested_column_ptr().get());
+                assert_cast<ColumnUInt8*>(
+                        assert_cast<ColumnNullable*>(column.get())->get_null_map_column_ptr().get())
+                        ->insert_many_defaults(max_step);
+            } else {
+                target = assert_cast<ColumnInt32*>(column.get());
+            }
+            auto origin_size = target->size();
+            target->resize(origin_size + max_step);
+            std::iota(target->get_data().data() + origin_size,
+                      target->get_data().data() + origin_size + max_step, _cur_offset);
         }
-
-        return TableFunction::get_value(column, max_step);
+        forward(max_step);
+        return max_step;
     }
 
 private:

From ecc46e2a24e9b4be42a34cac0fd45ce3d47701cb Mon Sep 17 00:00:00 2001
From: HappenLee <happenlee@hotmail.com>
Date: Thu, 18 Apr 2024 01:03:26 +0800
Subject: [PATCH 2/2] fix 0 value

---
 .../exprs/table_function/vexplode_numbers.h   | 32 ++++++++++++-------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/be/src/vec/exprs/table_function/vexplode_numbers.h b/be/src/vec/exprs/table_function/vexplode_numbers.h
index a60feba1adc5ab..1890719c689aa6 100644
--- a/be/src/vec/exprs/table_function/vexplode_numbers.h
+++ b/be/src/vec/exprs/table_function/vexplode_numbers.h
@@ -60,20 +60,28 @@ class VExplodeNumbersTableFunction : public TableFunction {
                         ->insert_range_from(*_elements_column, _cur_offset, max_step);
             }
         } else {
-            ColumnInt32* target = nullptr;
-            if (_is_nullable) {
-                target = assert_cast<ColumnInt32*>(
-                        assert_cast<ColumnNullable*>(column.get())->get_nested_column_ptr().get());
-                assert_cast<ColumnUInt8*>(
-                        assert_cast<ColumnNullable*>(column.get())->get_null_map_column_ptr().get())
-                        ->insert_many_defaults(max_step);
+            // should dispose the empty status, forward one step
+            if (current_empty()) {
+                column->insert_default();
+                max_step = 1;
             } else {
-                target = assert_cast<ColumnInt32*>(column.get());
+                ColumnInt32* target = nullptr;
+                if (_is_nullable) {
+                    target = assert_cast<ColumnInt32*>(assert_cast<ColumnNullable*>(column.get())
+                                                               ->get_nested_column_ptr()
+                                                               .get());
+                    assert_cast<ColumnUInt8*>(assert_cast<ColumnNullable*>(column.get())
+                                                      ->get_null_map_column_ptr()
+                                                      .get())
+                            ->insert_many_defaults(max_step);
+                } else {
+                    target = assert_cast<ColumnInt32*>(column.get());
+                }
+                auto origin_size = target->size();
+                target->resize(origin_size + max_step);
+                std::iota(target->get_data().data() + origin_size,
+                          target->get_data().data() + origin_size + max_step, _cur_offset);
             }
-            auto origin_size = target->size();
-            target->resize(origin_size + max_step);
-            std::iota(target->get_data().data() + origin_size,
-                      target->get_data().data() + origin_size + max_step, _cur_offset);
         }
         forward(max_step);
         return max_step;