DB_Result::tableInfo() docs say as follows:  
------------------   
DB_Result::tableInfo() -- returns meta data about the    
result set    
Description    
mixed tableInfo (DB_Result $result [, mode $mode])    
...    
------------------ 
  
That is misleading, however: it cannot be called  
statically.  
  
  $res = $db->query( "select foo from bar" );    
  DB_Result::tableInfo( $res );    
   
fails with "Fatal error: Call to a member function on a  
non-object in DB.php on line 828"  
  
It must be called on an object:    
 
  $res = $db->query( "select * from hits where false" );   
  $ar = $res->tableInfo();   
  print_r( $ar );