Method classifyTable

frontend/src/lib/duckdb/utils/queryRouter.ts:199–240

* Classify a table reference as PostgreSQL, MotherDuck, or Local

(ref: TableReference)

   * Classify a table reference as PostgreSQL, MotherDuck, or Local
   */
  private classifyTable(ref: TableReference): { type: 'postgresql' | 'motherduck' | 'local'; connectionId?: string } {
    console.log(`[QueryRouter] Classifying table:`, ref);
    
    // Check if this matches a PostgreSQL virtual table
    for (const [tableKey, table] of this.postgresVirtualTables) {
      const schemaMatch = ref.schema === table.schemaName || (!ref.schema && table.schemaName === 'public');
      const tableMatch = ref.table === table.tableName;
      
      console.log(`[QueryRouter] Checking against PostgreSQL table:`, {
        virtualTable: table,
        schemaMatch,
        tableMatch,
        refSchema: ref.schema,
        refTable: ref.table
      });
      
      if (schemaMatch && tableMatch) {
        console.log(`[QueryRouter] Found PostgreSQL match:`, table.connectionId);
        return { type: 'postgresql', connectionId: table.connectionId };
      }
    }

    // Check if this is a MotherDuck database reference
    if (ref.database && this.motherduckDatabases.has(ref.database)) {
      console.log(`[QueryRouter] Found MotherDuck match:`, ref.database);
      return { type: 'motherduck' };
    }

    // Special MotherDuck database patterns
    if (ref.database && (
      ref.database.includes('my_db') || 
      ref.database.includes('sample_data') ||
      ref.database.startsWith('md:')
    )) {
      console.log(`[QueryRouter] Found MotherDuck pattern match:`, ref.database);
      return { type: 'motherduck' };
    }

    // Default to local
    console.log(`[QueryRouter] Defaulting to local for:`, ref);
    return { type: 'local' };
  }

  /**
   * Determine the final routing target based on classified tables