// effects: Determines if the childNode can be added as a child of the
// groupNode using te operation "opTypeToIsolate". E.g., if
// opTypeToIsolate is inner join, we can add child to group node if
// childNode and groupNode have the same multiconstantsets, i.e., they have
// the same selection condition
// Modifies groupNode to contain groupNode at the appropriate
// position (for LOJs, the child could be added to the beginning)
private bool TryAddChildToGroup(
CellTreeOpType opTypeToIsolate, CellTreeNode childNode,
OpCellTreeNode groupNode)
{
switch (opTypeToIsolate)
{
case CellTreeOpType.IJ:
// For Inner join, the constants of the node and
// the child must be the same, i.e., if the cells
// are producing exactly same tuples (same selection)
if (IsEquivalentTo(childNode, groupNode))
{
groupNode.Add(childNode);
return(true);
}
break;
case CellTreeOpType.LOJ:
// If one cell's selection condition subsumes
// another, we can use LOJ. We need to check for
// "subsumes" on both sides
if (IsContainedIn(childNode, groupNode))
{
groupNode.Add(childNode);
return(true);
}
else if (IsContainedIn(groupNode, childNode))
{
// child subsumes the whole group -- add it first
groupNode.AddFirst(childNode);
return(true);
}
break;
case CellTreeOpType.Union:
// If the selection conditions are disjoint, we can use UNION ALL
// We cannot use active domain here; disjointness is guaranteed only
// if we check the entire selection domain
if (IsDisjoint(childNode, groupNode))
{
groupNode.Add(childNode);
return(true);
}
break;
}
return(false);
}
private bool TryAddChildToGroup(
CellTreeOpType opTypeToIsolate,
CellTreeNode childNode,
OpCellTreeNode groupNode)
{
switch (opTypeToIsolate)
{
case CellTreeOpType.Union:
if (this.IsDisjoint(childNode, (CellTreeNode)groupNode))
{
groupNode.Add(childNode);
return(true);
}
break;
case CellTreeOpType.LOJ:
if (this.IsContainedIn(childNode, (CellTreeNode)groupNode))
{
groupNode.Add(childNode);
return(true);
}
if (this.IsContainedIn((CellTreeNode)groupNode, childNode))
{
groupNode.AddFirst(childNode);
return(true);
}
break;
case CellTreeOpType.IJ:
if (this.IsEquivalentTo(childNode, (CellTreeNode)groupNode))
{
groupNode.Add(childNode);
return(true);
}
break;
}
return(false);
}
// effects: Determines if the childNode can be added as a child of the
// groupNode using te operation "opTypeToIsolate". E.g., if
// opTypeToIsolate is inner join, we can add child to group node if
// childNode and groupNode have the same multiconstantsets, i.e., they have
// the same selection condition
// Modifies groupNode to contain groupNode at the appropriate
// position (for LOJs, the child could be added to the beginning)
private bool TryAddChildToGroup(
CellTreeOpType opTypeToIsolate, CellTreeNode childNode,
OpCellTreeNode groupNode)
{
switch (opTypeToIsolate)
{
case CellTreeOpType.IJ:
// For Inner join, the constants of the node and
// the child must be the same, i.e., if the cells
// are producing exactly same tuples (same selection)
if (IsEquivalentTo(childNode, groupNode))
{
groupNode.Add(childNode);
return true;
}
break;
case CellTreeOpType.LOJ:
// If one cell's selection condition subsumes
// another, we can use LOJ. We need to check for
// "subsumes" on both sides
if (IsContainedIn(childNode, groupNode))
{
groupNode.Add(childNode);
return true;
}
else if (IsContainedIn(groupNode, childNode))
{
// child subsumes the whole group -- add it first
groupNode.AddFirst(childNode);
return true;
}
break;
case CellTreeOpType.Union:
// If the selection conditions are disjoint, we can use UNION ALL
// We cannot use active domain here; disjointness is guaranteed only
// if we check the entire selection domain
if (IsDisjoint(childNode, groupNode))
{
groupNode.Add(childNode);
return true;
}
break;
}
return false;
}
