Selecting parent nodes with XMLReader

Question

I had to rewrite part of a programme to use XMLReader to select parts of an XML file for processing.

Take this simplified XML as an example:

Answer 1

DOMXPath is said to be more robust than SimpleXML with respect to performance (it has other advantages, e.g. it can properly deal with namespaces). See for example this IBM article for a discussion of several XPath libraries in PHP.

I'm just curious if your performance issue would persist (or still be as severe) when using DOMXPath:

load('sample.xml');
$xpath = new DOMXPath($doc);

$nodes = $xpath->query("/odds/sport/region/group/event/bet[selection/@selectionid = '52411062.1']");

foreach ($nodes as $node)
{
   print $xml = $node->ownerDocument->saveXML($node);
}
?>

The result, taking as input the small snippet you have shown, is

If that does not help, you really have to resort to an event-based (pull-style) XML parser, that does not read the whole document into memory - as Yasen suggests.