Help in designing mysql table for large project I am planning to create a website which allows different Companies to register in it. It will have Employees module. Each company will have a CompanyId. How do I maintain the Employees table, since in near future data sets may go extremely large. Kindly suggest which is appropriate. I am listing my intended designs, kindly suggest a better one .

Note : The Employees of one company has no relation with employees of other companies.


    Companies Table

    CompanyId CompanyName
    1       A
    2       B
    3       C


Employees Table

DESIGN 1:

DB : Companymanagement
Table Name : Employee 



  Here the employees for a company are identified from the companyId



    EmployeeId      CompanyId   EmployeeName
    1       1(from companies table) Employee-A
    2       2(from companies table) Employee-B
    3       2(from companies table) Employee-C



DESIGN 2:

DB : Companymanagement
Table Name : Employee_1



    EmployeeId      EmployeeName
    1               Employee-A
    2               Employee-B
    3               Employee-C

    Table Name : Employee_2
    EmployeeId      EmployeeName
    1       Employee-A
    2       Employee-B
    3       Employee-C



  Here the employees for a company are stored in individual tables with
  companyid in table name ex Employee_1


DESIGN 3:

DB : Companymanagement_1
Table Name : Employee



    EmployeeId      EmployeeName
    1       Employee-A
    2       Employee-B
    3       Employee-C


DB : Companymanagement_2
Table Name : Employee 



    EmployeeId      EmployeeName
        1           Employee-A
        2           Employee-B
        3           Employee-C



  Here, the employees for a company are stored in individual databases
  with companyid in database name ex Companymanagement_1


Kindly suggest me the right direction to manage datas. Sorry if I am vague.
If there is a possibility of an employee to work in many companies such as Advisor or Instructor, the above designs will fail. 
There are possibilitites where one employee can work in more than one company. 

So the perfect design would be the below

Company_Id   Company_Name
   1          Aaaa
   2          Bbbb 
   3          cccc


Employee_Id   Employee_Name
   11          A
   22          B 
   33          c


Company_Id   Employee_Id
   1          11
   2          22
   3          33
   3          22

This works in both the ways. One employee can work in many companies and many companies can have same employee. Many to Many relationship .