money without backwards compatibility2

common/proto/table_definition.proto

@@ -78,9 +78,8 @@ message PostTableDefinitionRequest {
   // like "public", "information_schema", or ones starting with "pg_".
   string profile_name = 5;
 
+  // ISO-4217 base currency used by every MONEY column in this table.
   string base_currency = 6;
-  repeated MoneyColumnOptions money_columns = 7;
-
 }
 
 // Defines append-only column additions for an existing table.
@@ -97,8 +96,8 @@ message AddTableColumnsRequest {
   // Optional indexes for the new columns only.
   repeated string indexes = 4;
 
-  repeated MoneyColumnOptions money_columns = 5;
-  string base_currency = 6;
+  // Required when adding the first MONEY column to a table.
+  string base_currency = 5;
 
 }
 
@@ -107,12 +106,6 @@ enum MoneyRounding {
   MONEY_ROUNDING_HALF_UP = 1;
 }
 
-message MoneyColumnOptions {
-  string column_name = 1;
-  bool immutable = 2;
-  MoneyRounding rounding = 3;
-}
-
 // Describes one user-defined column for a table.
 message ColumnDefinition {
   // Column name that follows the same validation rules as table_name.
@@ -132,6 +125,12 @@ message ColumnDefinition {
   // DECIMAL args must be integers (no sign, no dot, no leading zeros);
   // s ≤ p and p ≥ 1.
   string field_type = 2;
+
+  // Once initially stored, this column can never be changed.
+  bool immutable = 3;
+
+  // MONEY rounding applied before an immutable value is initially stored.
+  MoneyRounding rounding = 4;
 }
 
 // Response after table creation (success + DDL preview).
@@ -229,7 +228,6 @@ message TableDetail {
   repeated ColumnDefinition columns = 3;
   repeated ScriptInfo scripts = 4;
   string base_currency = 5;
-  repeated MoneyColumnOptions money_columns = 6;
 }
 
 // A script that targets a specific column in a table.