Use Inherrtance or not, a table desing question

Hi,

I am working on DB table design for an application. In the application, the search is based on sex: male or female. To
have a better performance, I am thinking about to have two profile tables for each sex. Since the most of data fields of
the two tables are identical, for the design point of view, it is better to use the inheritance, that will have three tables:
person table and two its children tables: male and female. I am very new to Postgres and don't know any its internal
structure. Please enlighten me whether I shall use the inheritance for a large size of data.

Thanks,

Vernon