I have table,

Table Book

id,name,buyers

And each row has the list of buyers.

buyers are about 100000.

So now I have two ideas.

First one is

Push the array of 100000 elements in row

id, name,       buyers
 1, nice story,[1042,13534,14534,15353,,,,,.....]

Second one is

Make another table

Table Buyers

buyer_id, book_id
1042   , 1
13534  , 1
14534  , 1
15353  , 1

I guess total database size is small for Idea 1 but it’s not good way to handle such a big array ?

Which one is faster and best practice?