XPost: microsoft.public.sqlserver.server   
   From: genew@ocis.net   
      
   Hello:   
      
        The text that I am studying is Robin Dewson's "Beginning SQL   
   Server 2008 Express for Developers From Novice to Professional"   
   published by Apress.  It generally quite readable, but I am running   
   into some trouble in the chapter on backups.  I have checked Books   
   Online for some of this, but to no avail.   
      
        Because I do have some confusion here, my questions might not   
   quite be correct for what I need.  I want the basic terms, not the ins   
   and outs of how they are used.  If I get that, then my text will   
   probably make much more sense for the rest.   
      
     1) I need some definitions:   
             physical log  (I think this a fixed-length file.)   
             logical log   
             virtual log   
      
     2) My understanding of the term "transaction log" is that such a log   
   would be preserved until a backup is done, but the text has   
   conflicting statements.  There is something about a checkpoint.  When   
   is truncating a transaction log is done by SSE?   
      
     3) When are committed transactions used to update the tables?  I   
   would have thought that this would happen fairly often, but the text   
   has some apparently conflicting statements.  What is the significance   
   of a "transaction log backup" (contra any other)?   
      
   Sincerely,   
      
   Gene Wirchenko   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)