Feature: #79387 - Add signal to exclude tables from ReferenceIndex

Description

A new signal shouldExcludeTableFromReferenceIndex is emitted in \TYPO3\CMS\Core\Database\ReferenceIndex which allows extensions to define tables which should be excluded from ReferenceIndex.

Register the class which excludes tables in ext_localconf.php:

$dispatcher = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\SignalSlot\Dispatcher::class);
$dispatcher->connect(
    \TYPO3\CMS\Core\Database\ReferenceIndex::class,
    'shouldExcludeTableFromReferenceIndex',
    \MyVendor\MyExtension\Slots\ReferenceIndexSlot::class,
    'shouldExcludeTableFromReferenceIndex'
);

Your class could look like this:

namespace MyVendor\MyExtension\Slot;

class ReferenceIndexSlot {

   /**
    * Exclude tables from ReferenceIndex which cannot contain a reference
    *
    * @param string $tableName Name of the table
    * @param bool &$excludeTable Reference to a boolean whether to exclude the table from ReferenceIndex or not
    */
   public function shouldExcludeTableFromReferenceIndex($tableName, &$excludeTable) {
      if ($tableName === 'tx_myextension_mytable') {
         $excludeTable = true;
      }
   }

}

Impact

This signal allows extensions to speed up the process of maintaining the ReferenceIndex. If an extension has tables in which by definition none of its columns can contain any relations to other records these can be excluded from the ReferenceIndex.

Only exclude tables from ReferenceIndex which do not contain any relations and never did since existing references won't be deleted if it is excluded! There is no need to add tables without a definition in $GLOBALS['TCA] since ReferenceIndex only handles those.