Go through queries in chunks so you don't run out of memory

ChunkLoop.php

<?php

$offset = 0;
// only process 1000 at a time
$increment = 1000;

// getByOffsetAndLimit is the key factor here!
while ($galleries = $this->listingGalleryRepository->getByOffsetAndLimit($offset, $increment)) {
    
    // we have to break out of the loop if there are no more left
    if (count($listingGalleries) === 0) {
        break;
    }
    
    foreach ($galleries as $gallery) {
        // do something with each gallery in this chunk...
    }

    // update the offset by the chunk increment
    $offset += $increment;
}