TYPO3 Core

I can confirm this. IRRE is currently loading everything.
Better would be to load only visible data - that implies that "appearance/collapseAll" has to be used when only visibles are fetched from storage.

Could you please post the TCA setting of the IRRE field on the pages table?

Here are my settings done in the ext_tables.php:

$tempColumns = Array (
'user_mgproducts_material' => Array (
'exclude' => 1,
'label' => 'LLL:EXT:user_mgproducts/locallang_db.xml:user_mgproducts_material_rel.product_id',
'config' => Array (
'type' => 'inline',
'foreign_table' => 'user_mgproducts_appearence_rel',
'foreign_field' => 'page_id',
'foreign_sortby' => 'pagesort',
'foreign_label' => 'product_id',
'foreign_unique' => 'product_id',
'maxitems' => 5000,
'appearance' => Array ('useSortable' => 1,),
)
),
);

t3lib_div::loadTCA('pages');
t3lib_extMgm::addTCAcolumns('pages',$tempColumns,1);
t3lib_extMgm::addToAllTCAtypes('pages','user_mgproducts_material;;;;1-1-1');