private static FragmentQuery GenerateFragmentQuery(IEnumerable <CellTreeNode> children, bool isLeft, ViewgenContext context, CellTreeOpType OpType)
{
Debug.Assert(children.Any());
FragmentQuery fragmentQuery = isLeft ? children.First().LeftFragmentQuery : children.First().RightFragmentQuery;
FragmentQueryProcessor qp = isLeft ? context.LeftFragmentQP : context.RightFragmentQP;
foreach (var child in children.Skip(1))
{
FragmentQuery nextQuery = isLeft ? child.LeftFragmentQuery : child.RightFragmentQuery;
switch (OpType)
{
case CellTreeOpType.IJ:
fragmentQuery = qp.Intersect(fragmentQuery, nextQuery);
break;
case CellTreeOpType.LOJ:
// Left outer join means keeping the domain of the leftmost child
break;
case CellTreeOpType.LASJ:
// not used in basic view generation but current validation calls Simplify, so add this for debugging
fragmentQuery = qp.Difference(fragmentQuery, nextQuery);
break;
default:
// All other operators (Union, FOJ) require union of the domains
fragmentQuery = qp.Union(fragmentQuery, nextQuery);
break;
}
}
return(fragmentQuery);
}
private static FragmentQuery GenerateFragmentQuery(
IEnumerable <CellTreeNode> children,
bool isLeft,
ViewgenContext context,
CellTreeOpType OpType)
{
FragmentQuery fragmentQuery1 = isLeft ? children.First <CellTreeNode>().LeftFragmentQuery : children.First <CellTreeNode>().RightFragmentQuery;
FragmentQueryProcessor fragmentQueryProcessor = isLeft ? context.LeftFragmentQP : context.RightFragmentQP;
foreach (CellTreeNode cellTreeNode in children.Skip <CellTreeNode>(1))
{
FragmentQuery fragmentQuery2 = isLeft ? cellTreeNode.LeftFragmentQuery : cellTreeNode.RightFragmentQuery;
switch (OpType)
{
case CellTreeOpType.LOJ:
continue;
case CellTreeOpType.IJ:
fragmentQuery1 = fragmentQueryProcessor.Intersect(fragmentQuery1, fragmentQuery2);
continue;
case CellTreeOpType.LASJ:
fragmentQuery1 = fragmentQueryProcessor.Difference(fragmentQuery1, fragmentQuery2);
continue;
default:
fragmentQuery1 = fragmentQueryProcessor.Union(fragmentQuery1, fragmentQuery2);
continue;
}
}
return(fragmentQuery1);
}
