multiple requests to the structure of a tables at once(batching)

common/proto/table_structure.proto

@@ -4,40 +4,45 @@ package komp_ac.table_structure;
 
 import "common.proto";
 
-// Introspects the physical PostgreSQL table for a given logical table
-// (defined in table_definitions) and returns its column structure.
+// Introspects the physical PostgreSQL tables for one or more logical tables
+// (defined in table_definitions) and returns their column structures.
 // The server validates that:
 // - The profile (schema) exists in `schemas`
-// - The table is defined for that profile in `table_definitions`
-// It then queries information_schema for the physical table and returns
-// normalized column metadata. If the physical table is missing despite
-// a definition, the response may contain an empty `columns` list.
+// - Every table is defined for that profile in `table_definitions`
+// It then queries information_schema for the physical tables and returns
+// normalized column metadata.
 service TableStructureService {
   // Return the physical column list (name, normalized data_type,
-  // nullability, primary key flag) for a table in a profile.
+  // nullability, primary key flag) for one or more tables in a profile.
   //
   // Behavior:
   // - NOT_FOUND if profile doesn't exist in `schemas`
-  // - NOT_FOUND if table not defined for that profile in `table_definitions`
+  // - NOT_FOUND if any table is not defined for that profile in `table_definitions`
   // - Queries information_schema.columns ordered by ordinal position
   // - Normalizes data_type text (details under TableColumn.data_type)
-  // - Returns an empty list if the table is validated but has no visible
-  //   columns in information_schema (e.g., physical table missing)
-  rpc GetTableStructure(GetTableStructureRequest) returns (TableStructureResponse);
+  // - Returns an error if any validated table has no visible columns in
+  //   information_schema (e.g., physical table missing)
+  rpc GetTableStructure(GetTableStructureRequest) returns (GetTableStructureResponse);
 }
 
-// Request identifying the profile (schema) and table to inspect.
+// Request identifying the profile (schema) and tables to inspect.
 message GetTableStructureRequest {
   // Required. Profile (PostgreSQL schema) name. Must exist in `schemas`.
   string profile_name = 1;
 
-  // Required. Table name within the profile. Must exist in `table_definitions`
-  // for the given profile. The physical table is then introspected via
-  // information_schema.
-  string table_name = 2;
+  // Required. Table names within the profile. Each must exist in
+  // `table_definitions` for the given profile. The physical tables are then
+  // introspected via information_schema.
+  repeated string table_names = 2;
 }
 
-// Response with the ordered list of columns (by ordinal position).
+// Batched response keyed by table name.
+message GetTableStructureResponse {
+  // Per-table physical column lists keyed by requested table name.
+  map<string, TableStructureResponse> table_structures = 1;
+}
+
+// Response with the ordered list of columns (by ordinal position) for one table.
 message TableStructureResponse {
   // Columns of the physical table, including system columns (id, deleted,
   // created_at), user-defined columns, and any foreign-key columns such as