private Page readPage(int pageNumber)
     throws DbException, TransactionAbortedException, IOException {
   // File == table because we do one file per table
   //	System.out.println("readpage:"+_file.id()+" page:"+pageNumber);
   int tableId = _file.id();
   int pageId = pageNumber;
   //	System.out.println("Page is now "+pageNumber);
   HeapPageId pid = new HeapPageId(tableId, pageId);
   return Database.getBufferPool().getPage(_transactionId, pid, Permissions.READ_ONLY);
 }