Performance of Tables vs. Views

Question

Recently started working with a database in which the convention is to create a view for every table. If you assume that there is a one to one mapping between tables and views,

Answer 1

You don't explain what you're doing in the views? A 1:1 with the tables sounds like you are using the views more like synonyms than a view. IOW, are the views = "SELECT * FROM table", then you'll see no performance hit except on hard parse.

If you are joining to other tables or placing filter clauses in them which prevent predicate pushing than you're bound to see a major hit sometime.