Display problem when the database becomes large

THANKS SAchin for replay
I am a beginner can you explain how use  my function get_allStatEntite and fillStatPosteDataTable in that case
$(document).ready(function() {
$('#example').DataTable( {
serverSide: true,
ordering: false,
searching: false,
ajax: function ( data, callback, settings ) {
var out = [];
for ( var i=data.start, ien=data.start+data.length ; i out.push( [ i+'-1', i+'-2', i+'-3', i+'-4', i+'-5' ] );
}
setTimeout( function () {
callback( {
draw: data.draw,
data: out,
recordsTotal: 5000000,
recordsFiltered: 5000000
} );
}, 50 );
},
scrollY: 200,
scroller: {
loadingIndicator: true
},
} );
} );