// returns true if no more extra tuples are left
private bool TryJoin(T_Tile view, ref T_Tile rewriting)
{
T_Tile newRewriting = m_qp.Join(rewriting, view);
if (!m_qp.IsEmpty(newRewriting))
{
m_usedViews[view] = TileOpKind.Join;
rewriting = newRewriting;
return(m_qp.IsDisjointFrom(rewriting, m_toAvoid));
}
return(false);
}
private T_Tile GetRewritingHalf(T_Tile halfRewriting, T_Tile remainingView, TileOpKind viewKind)
{
switch (viewKind)
{
case TileOpKind.Join:
halfRewriting = m_qp.Join(halfRewriting, remainingView); break;
case TileOpKind.AntiSemiJoin:
halfRewriting = m_qp.AntiSemiJoin(halfRewriting, remainingView); break;
case TileOpKind.Union:
halfRewriting = m_qp.Union(halfRewriting, remainingView); break;
default: Debug.Fail("unexpected"); break;
}
return(halfRewriting);
}
