Merge arrays without causing server overload

Merge arrays without causing server overload.

Whenever you merge two arrays with large datasets, it becomes a severe strain on the server while merging the arrays. When using the Array.concat function on larger data sets, it will consume much memory while creating a new array. To get around the performance drop, use Array.push.apply(arr1, arr2) which consolidates the second array into the first one without creating a new array.