Attribute table cache size 0 is represented as "All" in the options

src/app/qgsoptions.cpp

@@ -308,6 +308,7 @@ QgsOptions::QgsOptions( QWidget *parent, Qt::WindowFlags fl ) :
 
 
   spinBoxAttrTableRowCache->setValue( settings.value( "/qgis/attributeTableRowCache", 10000 ).toInt() );
+  spinBoxAttrTableRowCache->setSpecialValueText( tr( "All" ) );
 
   // set the prompt for raster sublayers
   // 0 = Always -> always ask (if there are existing sublayers)