From 3dcdadcea656991839c9e7ffed4beb20ae4f0149 Mon Sep 17 00:00:00 2001
From: Gabriel <gabrielleebuaa@gmail.com>
Date: Mon, 22 May 2023 22:48:44 +0800
Subject: [PATCH] [Improvement](function) support decimalv3 for function
 `least` and `greatest` (#19931)

---
 be/src/vec/functions/least_greast.cpp         | 26 +++++++++++++++++--
 .../doris/analysis/FunctionCallExpr.java      |  4 ++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/be/src/vec/functions/least_greast.cpp b/be/src/vec/functions/least_greast.cpp
index 26f168ad68..90f8fa99cf 100644
--- a/be/src/vec/functions/least_greast.cpp
+++ b/be/src/vec/functions/least_greast.cpp
@@ -110,7 +110,7 @@ struct CompareMultiImpl {
         }                                                                                         \
     }
             NUMERIC_TYPE_TO_COLUMN_TYPE(DISPATCH)
-            DISPATCH(Decimal128, ColumnDecimal<Decimal128>)
+            DECIMAL_TYPE_TO_COLUMN_TYPE(DISPATCH)
             TIME_TYPE_TO_COLUMN_TYPE(DISPATCH)
 #undef DISPATCH
         }
@@ -136,6 +136,17 @@ private:
                                 ? column_raw_data[index_check_const(i, ArgConst)]
                                 : result_raw_data[i];
             }
+        } else if constexpr (std::is_same_v<ColumnType, ColumnDecimal32> ||
+                             std::is_same_v<ColumnType, ColumnDecimal64> ||
+                             std::is_same_v<ColumnType, ColumnDecimal128I>) {
+            for (size_t i = 0; i < input_rows_count; ++i) {
+                using type = std::decay_t<decltype(result_raw_data[0].value)>;
+                result_raw_data[i] =
+                        Op<type, type>::apply(column_raw_data[index_check_const(i, ArgConst)].value,
+                                              result_raw_data[i].value)
+                                ? column_raw_data[index_check_const(i, ArgConst)]
+                                : result_raw_data[i];
+            }
         } else {
             for (size_t i = 0; i < input_rows_count; ++i) {
                 using type = std::decay_t<decltype(result_raw_data[0])>;
@@ -204,7 +215,7 @@ struct FunctionFieldImpl {
         }                                                                                       \
     }
             NUMERIC_TYPE_TO_COLUMN_TYPE(DISPATCH)
-            DISPATCH(Decimal128, ColumnDecimal<Decimal128>)
+            DECIMAL_TYPE_TO_COLUMN_TYPE(DISPATCH)
             TIME_TYPE_TO_COLUMN_TYPE(DISPATCH)
 #undef DISPATCH
         }
@@ -230,6 +241,17 @@ private:
                                         first_raw_data[index_check_const(i, ArgConst)], arg_data)) *
                                 col);
             }
+        } else if constexpr (std::is_same_v<ColumnType, ColumnDecimal32> ||
+                             std::is_same_v<ColumnType, ColumnDecimal64> ||
+                             std::is_same_v<ColumnType, ColumnDecimal128I>) {
+            for (size_t i = 0; i < input_rows_count; ++i) {
+                using type = std::decay_t<decltype(first_raw_data[0].value)>;
+                res_data[i] |= (!res_data[i] *
+                                (EqualsOp<type, type>::apply(
+                                        first_raw_data[index_check_const(i, ArgConst)].value,
+                                        arg_data.value)) *
+                                col);
+            }
         } else {
             for (size_t i = 0; i < input_rows_count; ++i) {
                 using type = std::decay_t<decltype(first_raw_data[0])>;
diff --git a/fe/fe-core/src/main/java/org/apache/doris/analysis/FunctionCallExpr.java b/fe/fe-core/src/main/java/org/apache/doris/analysis/FunctionCallExpr.java
index 51abe66cbc..1238c8514e 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/analysis/FunctionCallExpr.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/analysis/FunctionCallExpr.java
@@ -1403,7 +1403,9 @@ public class FunctionCallExpr extends Expr {
             }
             fn = getBuiltinFunction(fnName.getFunction(), childTypes,
                     Function.CompareMode.IS_NONSTRICT_SUPERTYPE_OF);
-        } else if (fnName.getFunction().equalsIgnoreCase("coalesce") && children.size() > 1) {
+        } else if ((fnName.getFunction().equalsIgnoreCase("coalesce")
+                || fnName.getFunction().equalsIgnoreCase("greatest")
+                || fnName.getFunction().equalsIgnoreCase("least")) && children.size() > 1) {
             Type[] childTypes = collectChildReturnTypes();
             Type assignmentCompatibleType = childTypes[0];
             for (int i = 1; i < childTypes.length && assignmentCompatibleType.isDecimalV3(); i++) {