[Fix](variant) fallback to none partial update for mow table (#28116)

fe/fe-core/src/main/java/org/apache/doris/analysis/UpdateStmt.java

@@ -189,8 +189,12 @@ public class UpdateStmt extends DdlStmt {
 
         // step3: generate select list and insert column name list in insert stmt
         boolean isMow = ((OlapTable) targetTable).getEnableUniqueKeyMergeOnWrite();
+        boolean hasVariant = false;
         int setExprCnt = 0;
         for (Column column : targetTable.getColumns()) {
+            if (column.getType().isVariantType()) {
+                hasVariant = true;
+            }
             for (BinaryPredicate setExpr : setExprs) {
                 Expr lhs = setExpr.getChild(0);
                 if (((SlotRef) lhs).getColumn().equals(column)) {
@@ -198,10 +202,13 @@ public class UpdateStmt extends DdlStmt {
                 }
             }
         }
-        // table with sequence col cannot use partial update cause in MOW, we encode pk
+        // 1.table with sequence col cannot use partial update cause in MOW, we encode pk
         // with seq column but we don't know which column is sequence in update
+        // 2. variant column update schema during load, so implement partial update is complicated,
+        //  just ignore it at present
         if (isMow && ((OlapTable) targetTable).getSequenceCol() == null
-                && setExprCnt <= targetTable.getColumns().size() * 3 / 10) {
+                && setExprCnt <= targetTable.getColumns().size() * 3 / 10
+                && !hasVariant) {
             isPartialUpdate = true;
         }
         for (Column column : targetTable.getColumns()) {

regression-test/data/variant_p0/delete_update.out

@@ -7,4 +7,10 @@
 
 -- !sql --
 2	{"updated_value":123}	{"updated_value":123}
+6	{"c":4.0,"a":4,"b":[4]}	{"updated_value" : 123}
+7	{"updated_value":1111}	yyy
+
+-- !sql --
+2	{"updated_value":123}	{"updated_value":123}
+6	{"c":4.0,"a":4,"b":[4]}	{"updated_value" : 123}
 

regression-test/suites/variant_p0/delete_update.groovy

@@ -55,9 +55,14 @@ suite("regression_test_variant_delete_and_update", "variant_type"){
     sql "insert into var_delete_update_mow select k, cast(v as string), cast(v as string) from var_delete_update"
     sql "delete from ${table_name} where k = 1"
     sql "delete from ${table_name} where k in (select k from var_delete_update_mow where k in (3, 4, 5))"
-    // FIXME
-    // sql """update ${table_name} set vs = '{"updated_value" : 123}' where k = 2"""
-    // sql """update ${table_name} set v = '{"updated_value" : 123}' where k = 2"""
+
+    sql """insert into ${table_name} values (6, '{"a" : 4, "b" : [4], "c": 4.0}', 'xxx')"""
+    sql """insert into ${table_name} values (7, '{"a" : 4, "b" : [4], "c": 4.0}', 'yyy')"""
+    sql """update ${table_name} set vs = '{"updated_value" : 123}' where k = 6"""
+    sql """update ${table_name} set v = '{"updated_value" : 1111}' where k = 7"""
+    qt_sql "select * from ${table_name} order by k"
+
+    sql """delete from ${table_name} where vs = 'xxx' or vs = 'yyy'"""
     qt_sql "select * from ${table_name} order by k"
 
     // delete & insert concurrently