mysql - Separate user data from other data -

our client user table separated other tables "security reasons". practice given our application built using ror , mysql , running on unicorn , nginx ?

i can think of 2 possible ways:

• create 2 different login accounts, 1 user table , 1 other tables.

or

• have separate database user data.

i think both solutions might create problems migrations , other tasks , don't know if effective method of protecting user data. junior developer , not familiar database , security concepts. suggestion?

a common pattern have users table literally contain details of user account , no details of actual person behind account. ie, have username, email, password, or encrypted password & salt or whatever, nothing else - not name. so, "glue" makes system work stays in users table in regular database.

then, details of real person behind account (name, telephone number, address, card details etc etc) stored in different table, or tables, foreign key in either table pointing other one. store them in different database don't know if makes more secure. better way might encrypt table user's personal data, or perhaps encrypt entire database. see

http://thinkdiff.net/mysql/encrypt-mysql-data-using-aes-techniques/

i feeling client doesn't know lot internet security , needs reassured hacker isn't going put customers' credit card details online, has happened in several high profile cases recently. satisfy them recommend research , implement @ least 2 different security strategies, each of on own considered adequate.