when to use the SPSite and SPweb from context or when to create a new instance?

Question

I already read the document about disposal about 10 times in the last 3 years. But my question is different.

Why wouldnt I always use SPContext.Site and .Web

instead of always creating an object instance? using (SPSite site =

I suppose it has to do with the kind of operations you are going to do with the objects? As far as I know creating an instance its more resource intensive, so the more I use the Context object the better?

Answer 1

Also create new SPSite and SPWeb inside of RunWithElevatedPrivileges. SPSite object permissions are determined when they are created, so SPContext.Current.Site will already have the permissions of the current user even if you get the reference within RWEP.

Answer 2

I create a new SPSite or SPWeb instance when I don't have a SPContext (console app, powershell, unit test, etc) or I need to get data from a different SPSite and SPWeb than the one I'm currently accessing.