23.8 Backport of #57395 - Fix ALTER COLUMN with ALIAS

src/Storages/AlterCommands.cpp

@@ -1148,7 +1148,7 @@ void AlterCommands::validate(const StoragePtr & table, ContextPtr context) const
             /// So we don't allow to do it for now.
             if (command.data_type)
             {
-                const GetColumnsOptions options(GetColumnsOptions::AllPhysical);
+                const GetColumnsOptions options(GetColumnsOptions::All);
                 const auto old_data_type = all_columns.getColumn(options, column_name).type;
 
                 bool new_type_has_object = command.data_type->hasDynamicSubcolumns();

tests/queries/0_stateless/02908_alter_column_alias.reference

@@ -0,0 +1 @@
+CREATE TABLE default.t\n(\n    `c0` DateTime,\n    `c1` DateTime,\n    `a` DateTime ALIAS c1\n)\nENGINE = MergeTree\nORDER BY tuple()\nSETTINGS index_granularity = 8192

tests/queries/0_stateless/02908_alter_column_alias.sql

@@ -0,0 +1,8 @@
+CREATE TABLE t (
+    c0 DateTime,
+    c1 DateTime,
+    a DateTime alias toStartOfFifteenMinutes(c0)
+) ENGINE = MergeTree() ORDER BY tuple();
+
+ALTER TABLE t MODIFY COLUMN a DateTime ALIAS c1;
+SHOW CREATE t;