advice for schema of a db for callcenter

[biagio rea]

I'm working on a db structure for a callcenter

after several changes I'm again asking if I have to review everything

There are two entities particularly numerous :

- companies_phone_records, millions of records containing the names of the companies

- telephone_calls, millions of records containing the calls to be processed: the id reference to the company, the user_operator, ...

I see as the alternative structures as possible:

(a) to use only a single table INNODB engine for the names and a single table for calls

(b) use MyISAM and break up the companies_phone and telephone_calls in as many tables by geographical area, and to make calculations based on all names using MERGE ... UNION

(c) ?

I'm currently using two InnoDB tables (a)
ps I'm using wamp server

thanks a lot from now for the advices