<p>Ok, i have simple scenario:</p>

<p>have two pages:
login and welcome pages.
im using FormsAuthentication with my own table that has four columns: ID, UserName, Password, FullName</p>

<p>When pressed login im setting my username like:</p>

<pre><code>FormsAuthentication.SetAuthCookie(userName, rememberMe ?? false);
</code></pre>

<p>on the welcome page i cant use:</p>

<pre><code>Page.User.Identity.Name
</code></pre>

<p>to provide to user which user currently logged, BUT i dont user username like at all examples in <a href="http://asp.net" rel="nofollow noreferrer">http://asp.net</a> web site i want to user FullName field</p>

<p>i think that always go to db and request fullname when page loads its crazy and dont like to user Sessions or Simple Cookie mayby FormsAuth provider has custom fields for this</p>

Forms authentication works using cookies.  You could construct your own auth cookie and put the full name in it, but I think I would go with putting it into the session.  If you use a cookie of any sort, you'll need to extract the name from it each time.   Tying it to the session seems more natural and makes it easy for you to access.  I agree that it seems a waste to go back to the DB every time and I would certainly cache the value somewhere.
Info on constructing your own forms authentication cookie can be found
here
.