OEM views meeting   1/29/97
Attendees: Serge, Jason, Roy, Vasilis, Yue.

We first discussed the problem when we want to keep relationship between
selected nodes in the view. We come up with about three ways to do the
view definition: 
(1) First select a larger group of nodes/edges then delete the unwanted
ones. 
(2) First select a necessary set of nodes/edges then add desired edges.
This may require automatic coercion between source objs and view objs.
(3) Use notion x@db to denote the 'original object' of x in the database DB.
The problem with this technique is that we need to prohibit the user to 
access this link and go from one database to another. However, this method be
useful when the added edges(nodes) are different from the one in the source
database. 


Then we discussed more on query rewriting. Especially, how to push some 
conditions from the query to the view definition such that the view 
becomes smaller (in size) and the query evaluation may be simpler. 
Vasilis gives some examples on this topic.