[TYPO3-dev] Question about overlay query condition

[Francois Suter]

Hi all,

The method t3lib_page::getRecordOverlay() is used to overlay a single 
record with its translation, if it exists.

The query that fetches the overlay record looks like this:

$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery(
	'*',
	$table,
	'pid='.intval($row['pid']).
		' AND 
'.$TCA[$table]['ctrl']['languageField'].'='.intval($sys_language_content).
		' AND 
'.$TCA[$table]['ctrl']['transOrigPointerField'].'='.intval($row['uid']).
		$this->enableFields($table),
	'',
	'',
	'1'
);

I'm puzzled about the condition on the pid. I don't see why it is 
necessary to test that the overlay record is on the same page as the 
original one, since we are already testing the original/translation 
relationship by comparing the transOrigPointerField to the original's uid.

Am I missing something?

I'm asking because I'm trying to optimise the overlay process, which 
currently requires 2 queries per record to overlay (one for the language 
overlay and one for the workspace overlay of the language overlay). 
Needless to say that this can kill performance. If the pid condition 
were not useful, it could be removed and all language overlays could be 
gotten in one go for a set of originals by testing transOrigPointerField 
with "IN" and a list of uid's from the original records.

Cheers

-- 

Francois Suter
Cobweb Development Sarl - http://www.cobweb.ch