We are building a project which is contains mobile apps for different platforms and also WordPress web site. It will contains a custom tables to store all the information which will be shown in both sides and for the WordPress we will build a new plug in to show that data from the tables. My question is what is the best place for the tables? Should we put them in the WordPress database or we should create new database for the tables?
You would want to keep all the data in one database if possible. Otherwise, you have to worry about keeping data across 2 databases in sync, which can be difficult. You have to do 2 of everyting. Updates, creates, deletes. Everything is doubled. So if you can, you should only have 1 database. Even if you have a separate DB for one data set and don't need to duplicate the data, it makes things easier to have one DB to connect to. I is easier to secure one DB instead of 2 or more.