Search against analyzed text vs keyword array field


I have a text field which contains millions of ids in comma separated,
EX :-
"field1: "1254,4578,578795,451546,3658,5689,........"

I'm currently analyzed above field with punctuation tokenizer and do the match queries to get what i want. But what happens if i split those values and store in keyword array,
I know keywords fields are best for aggregation but what would be fastest way for searching, analyzed text or keyword array field?