protected SearchPlanNode(PlanNode planNode)
{
NodeType = planNode.NodeType;
ElementID = planNode.ElementID;
IsPreset = planNode.IsPreset;
PatternElement = planNode.PatternElement;
}
public PlanEdge(SearchOperationType type, PlanNode source, PlanNode target, float cost)
{
Source = source;
Target = target;
Cost = cost;
mstCost = (float)Math.Max(Math.Log(cost), 1);
// mstCost = (float) Math.Max(Math.Log(cost), 0.0001);
// mstCost = cost;
Type = type;
}
/// <summary>
/// Instantiates an edge plan node.
/// </summary>
/// <param name="patEdge">The pattern edge for this plan node.</param>
/// <param name="elemID">The element ID for this plan node.</param>
/// <param name="isPreset">True, if this element is a known element.</param>
/// <param name="patternEdgeSource">The plan node corresponding to the source of the pattern edge.</param>
/// <param name="patternEdgeTarget">The plan node corresponding to the target of the pattern edge.</param>
public PlanNode(PatternEdge patEdge, int elemID, bool isPreset,
PlanNode patternEdgeSource, PlanNode patternEdgeTarget)
{
NodeType = PlanNodeType.Edge;
ElementID = elemID;
IsPreset = isPreset;
PatternElement = patEdge;
PatternEdgeSource = patternEdgeSource;
PatternEdgeTarget = patternEdgeTarget;
}
public readonly PlanEdge[] Edges; // edges of the plan graph, representing search operations
public PlanGraph(PlanNode root, PlanNode[] nodes, PlanEdge[] edges)
{
Root = root;
Nodes = nodes;
Edges = edges;
}
private void CreateSourceTargetIncomingOutgoingPlanEdges(PatternEdge edge, PlanNode planNode,
List<PlanEdge> planEdges, IDictionary<PatternNode, PatternNode> originalToInlinedIndependent,
LGSPGraphStatistics graphStatistics, PatternGraph patternGraph, bool isPreset, float zeroCost)
{
// only add implicit source operation if edge source is needed and the edge source is
// not a preset node and not a storage node and not an index node and not a cast node
PatternNode source = GetSourcePlusInlined(edge, patternGraph, originalToInlinedIndependent);
if(source != null
&& !source.TempPlanMapping.IsPreset
&& source.Storage == null
&& source.IndexAccess == null
&& source.NameLookup == null
&& source.UniqueLookup == null
&& source.ElementBeforeCasting == null)
{
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.ImplicitSource : SearchOperationType.Implicit;
PlanEdge implSrcPlanEdge = new PlanEdge(operation, planNode,
source.TempPlanMapping, zeroCost);
planEdges.Add(implSrcPlanEdge);
source.TempPlanMapping.IncomingEdges.Add(implSrcPlanEdge);
}
// only add implicit target operation if edge target is needed and the edge target is
// not a preset node and not a storage node and not an index node and not a cast node
PatternNode target = GetTargetPlusInlined(edge, patternGraph, originalToInlinedIndependent);
if(target != null
&& !target.TempPlanMapping.IsPreset
&& target.Storage == null
&& target.IndexAccess == null
&& target.NameLookup == null
&& target.UniqueLookup == null
&& target.ElementBeforeCasting == null)
{
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.ImplicitTarget : SearchOperationType.Implicit;
PlanEdge implTgtPlanEdge = new PlanEdge(operation, planNode,
target.TempPlanMapping, zeroCost);
planEdges.Add(implTgtPlanEdge);
target.TempPlanMapping.IncomingEdges.Add(implTgtPlanEdge);
}
// edge must only be reachable from other nodes if it's not a preset and not storage determined and not index determined and not a cast
if(!isPreset
&& edge.Storage == null
&& edge.IndexAccess == null
&& edge.NameLookup == null
&& edge.UniqueLookup == null
&& edge.ElementBeforeCasting == null)
{
// no outgoing on source node if no source
if(source != null)
{
int targetTypeID;
if(target != null) targetTypeID = target.TypeID;
else targetTypeID = model.NodeModel.RootType.TypeID;
// cost of walking along edge
#if MONO_MULTIDIMARRAY_WORKAROUND
float normCost = graphStatistics.vstructs[((source.TypeID * graphStatistics.dim1size + edge.TypeID) * graphStatistics.dim2size
+ targetTypeID) * 2 + (int)LGSPDirection.Out];
if(!edge.fixedDirection)
{
normCost += graphStatistics.vstructs[((source.TypeID * graphStatistics.dim1size + edge.TypeID) * graphStatistics.dim2size
+ targetTypeID) * 2 + (int)LGSPDirection.In];
}
#else
float normCost = graph.statistics.vstructs[source.TypeID, edge.TypeID, targetTypeID, (int) LGSPDirection.Out];
if (!edge.fixedDirection) {
normCost += graph.statistics.vstructs[source.TypeID, edge.TypeID, targetTypeID, (int) LGSPDirection.In];
}
#endif
if(graphStatistics.nodeCounts[source.TypeID] != 0)
normCost /= graphStatistics.nodeCounts[source.TypeID];
normCost = CostIncreaseForInlinedIndependent(edge, normCost);
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.Outgoing : SearchOperationType.Incident;
PlanEdge outPlanEdge = new PlanEdge(operation, source.TempPlanMapping,
planNode, normCost);
planEdges.Add(outPlanEdge);
planNode.IncomingEdges.Add(outPlanEdge);
}
// no incoming on target node if no target
if(target != null)
{
int sourceTypeID;
if(source != null) sourceTypeID = source.TypeID;
else sourceTypeID = model.NodeModel.RootType.TypeID;
// cost of walking in opposite direction of edge
#if MONO_MULTIDIMARRAY_WORKAROUND
float revCost = graphStatistics.vstructs[((target.TypeID * graphStatistics.dim1size + edge.TypeID) * graphStatistics.dim2size
+ sourceTypeID) * 2 + (int)LGSPDirection.In];
if(!edge.fixedDirection)
{
revCost += graphStatistics.vstructs[((target.TypeID * graphStatistics.dim1size + edge.TypeID) * graphStatistics.dim2size
+ sourceTypeID) * 2 + (int)LGSPDirection.Out];
}
#else
float revCost = graph.statistics.vstructs[target.TypeID, edge.TypeID, sourceTypeID, (int) LGSPDirection.In];
if (!edge.fixedDirection) {
revCost += graph.statistics.vstructs[target.TypeID, edge.TypeID, sourceTypeID, (int) LGSPDirection.Out];
}
#endif
if(graphStatistics.nodeCounts[target.TypeID] != 0)
revCost /= graphStatistics.nodeCounts[target.TypeID];
revCost = CostIncreaseForInlinedIndependent(edge, revCost);
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.Incoming : SearchOperationType.Incident;
PlanEdge inPlanEdge = new PlanEdge(operation, target.TempPlanMapping,
planNode, revCost);
planEdges.Add(inPlanEdge);
planNode.IncomingEdges.Add(inPlanEdge);
}
}
}
private static void CreatePlanNodeAndLookupPlanEdge(PatternEdge edge, int elemId,
LGSPGraphStatistics graphStatistics, PatternGraph patternGraph, bool isNegativeOrIndependent, bool isSubpatternLike, PlanNode planRoot, float zeroCost,
IDictionary<PatternNode, PatternNode> originalToInlinedIndependent, IDictionary<PatternElement, SetValueType> presetsFromIndependentInlining,
out bool isPreset, out PlanNode planNode, out PlanEdge rootToNodePlanEdge)
{
float cost;
SearchOperationType searchOperationType;
if(edge.DefToBeYieldedTo)
{
cost = zeroCost;
isPreset = true;
searchOperationType = SearchOperationType.DefToBeYieldedTo;
}
else if(edge.PointOfDefinition == null)
{
cost = zeroCost;
isPreset = true;
searchOperationType = isSubpatternLike ? SearchOperationType.SubPreset : SearchOperationType.ActionPreset;
}
else if(edge.PointOfDefinition != patternGraph && edge.OriginalIndependentElement == null)
{
cost = zeroCost;
isPreset = true;
searchOperationType = isNegativeOrIndependent ? SearchOperationType.NegIdptPreset : SearchOperationType.SubPreset;
}
else if(presetsFromIndependentInlining.ContainsKey(edge))
{
cost = zeroCost;
isPreset = true;
searchOperationType = SearchOperationType.NegIdptPreset;
edge.PresetBecauseOfIndependentInlining = true;
}
else if(edge.Storage != null)
{
if(edge.GetPatternElementThisElementDependsOnOutsideOfGraphConnectedness() != null)
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.Void; // the element we depend on is needed, so there is no lookup like operation
}
else
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.PickFromStorage; // pick from storage instead of lookup from graph
}
}
else if(edge.IndexAccess != null)
{
if(edge.GetPatternElementThisElementDependsOnOutsideOfGraphConnectedness() != null)
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.Void; // the element we depend on is needed, so there is no lookup like operation
}
else
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.PickFromIndex; // pick from index instead of lookup from graph
}
}
else if(edge.NameLookup != null)
{
if(edge.GetPatternElementThisElementDependsOnOutsideOfGraphConnectedness() != null)
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.Void; // the element we depend on is needed, so there is no lookup like operation
}
else
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.PickByName; // pick by name instead of lookup from graph
}
}
else if(edge.UniqueLookup != null)
{
if(edge.GetPatternElementThisElementDependsOnOutsideOfGraphConnectedness() != null)
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.Void; // the element we depend on is needed, so there is no lookup like operation
}
else
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.PickByUnique; // pick by unique instead of lookup from graph
}
}
else if(edge.ElementBeforeCasting != null)
{
cost = zeroCost;
isPreset = false;
searchOperationType = SearchOperationType.Void; // the element before casting is needed, so there is no lookup like operation
}
else
{
cost = graphStatistics.edgeCounts[edge.TypeID];
cost = CostIncreaseForInlinedIndependent(edge, cost);
isPreset = false;
searchOperationType = SearchOperationType.Lookup;
}
PatternNode source = GetSourcePlusInlined(edge, patternGraph, originalToInlinedIndependent);
PatternNode target = GetTargetPlusInlined(edge, patternGraph, originalToInlinedIndependent);
planNode = new PlanNode(edge, elemId, isPreset,
source != null ? source.TempPlanMapping : null,
target != null ? target.TempPlanMapping : null);
rootToNodePlanEdge = null;
if(searchOperationType != SearchOperationType.Void)
rootToNodePlanEdge = new PlanEdge(searchOperationType, planRoot, planNode, cost);
}
/// <summary>
/// Generate plan graph for given pattern graph with costs from the analyzed host graph.
/// Plan graph contains nodes representing the pattern elements (nodes and edges)
/// and edges representing the matching operations to get the elements by.
/// Edges in plan graph are given in the nodes by incoming list, as needed for MSA computation.
/// </summary>
public PlanGraph GeneratePlanGraph(LGSPGraphStatistics graphStatistics, PatternGraph patternGraph,
bool isNegativeOrIndependent, bool isSubpatternLike,
IDictionary<PatternElement, SetValueType> presetsFromIndependentInlining)
{
//
// If you change this method, chances are high you also want to change GenerateStaticPlanGraph in LGSPGrGen
// look there for version without ifdef junk
// todo: unify it with GenerateStaticPlanGraph in LGSPGrGen
//
// Create root node
// Create plan graph nodes for all pattern graph nodes and all pattern graph edges
// Create "lookup" plan graph edge from root node to each plan graph node
// Create "implicit source" plan graph edge from each plan graph node originating with a pattern edge
// to the plan graph node created by the source node of the pattern graph edge
// Create "implicit target" plan graph edge from each plan graph node originating with a pattern edge
// to the plan graph node created by the target node of the pattern graph edge
// Create "incoming" plan graph edge from each plan graph node originating with a pattern node
// to a plan graph node created by one of the incoming edges of the pattern node
// Create "outgoing" plan graph edge from each plan graph node originating with a pattern node
// to a plan graph node created by one of the outgoing edges of the pattern node
// Ensured: there's no plan graph edge with a preset element as target besides the lookup,
// so presets are only search operation sources
// Create "pick from storage" plan graph edge for plan graph nodes which are to be picked from a storage,
// from root node on, instead of lookup, no other plan graph edge having this node as target
// Create "pick from storage attribute" plan graph edge from storage attribute owner to storage picking result,
// no lookup, no other plan graph edge having this node as target
// Create "map" by storage plan graph edge from accessor to storage mapping result
// no lookup, no other plan graph edge having this node as target
// Create "pick from index" plan graph edge for plan graph nodes which are to be picked from an index,
// from root node on, instead of lookup, no other plan graph edge having this node as target
// Create "pick from index depending" plan graph edge from node the index expressions depend on,
// no lookup, no other plan graph edge having this node as target
// Create "cast" plan graph edge from element before casting to cast result,
// no lookup, no other plan graph edge having this node as target
int numNodes = patternGraph.nodesPlusInlined.Length;
if(InlineIndependents && !isNegativeOrIndependent)
numNodes += LGSPMatcherGenerator.NumNodesInIndependentsMatchedThere(patternGraph);
int numEdges = patternGraph.edgesPlusInlined.Length;
if(InlineIndependents && !isNegativeOrIndependent)
numEdges += LGSPMatcherGenerator.NumEdgesInIndependentsMatchedThere(patternGraph);
PlanNode[] planNodes = new PlanNode[numNodes + numEdges];
List<PlanEdge> planEdges = new List<PlanEdge>(numNodes + 5 * numEdges); // upper bound for num of edges (lookup nodes + lookup edges + impl. tgt + impl. src + incoming + outgoing)
Dictionary<PatternNode, PatternNode> originalToInlinedIndependent = new Dictionary<PatternNode, PatternNode>();
int nodesIndex = 0;
float zeroCost = 1;
PlanNode planRoot = new PlanNode("root");
// create plan nodes and lookup plan edges for all pattern graph nodes
for(int i = 0; i < patternGraph.nodesPlusInlined.Length; i++)
{
PatternNode node = patternGraph.nodesPlusInlined[i];
PlanNode planNode;
PlanEdge rootToNodePlanEdge;
CreatePlanNodeAndLookupPlanEdge(node, i + 1,
graphStatistics, patternGraph, isNegativeOrIndependent, isSubpatternLike, planRoot, zeroCost,
originalToInlinedIndependent, presetsFromIndependentInlining,
out planNode, out rootToNodePlanEdge);
planNodes[nodesIndex] = planNode;
if(rootToNodePlanEdge != null)
{
planEdges.Add(rootToNodePlanEdge);
planNode.IncomingEdges.Add(rootToNodePlanEdge);
}
node.TempPlanMapping = planNode;
++nodesIndex;
}
if(InlineIndependents && !isNegativeOrIndependent) // independent inlining only if not in negative/independent
{
foreach(PatternGraph independent in patternGraph.independentPatternGraphsPlusInlined)
{
foreach(PatternNode nodeOriginal in LGSPMatcherGenerator.NodesInIndependentMatchedThere(independent))
{
PatternNode node = new PatternNode(nodeOriginal, "_inlined_" + independent.name);
originalToInlinedIndependent.Add(nodeOriginal, node);
PlanNode planNode;
PlanEdge rootToNodePlanEdge;
CreatePlanNodeAndLookupPlanEdge(node, -1,
graphStatistics, patternGraph, isNegativeOrIndependent, isSubpatternLike, planRoot, zeroCost,
originalToInlinedIndependent, presetsFromIndependentInlining,
out planNode, out rootToNodePlanEdge);
planNodes[nodesIndex] = planNode;
if(rootToNodePlanEdge != null)
{
planEdges.Add(rootToNodePlanEdge);
planNode.IncomingEdges.Add(rootToNodePlanEdge);
}
node.TempPlanMapping = planNode;
++nodesIndex;
}
}
}
// create plan nodes and lookup plus incidence handling plan edges for all pattern graph edges
for(int i = 0; i < patternGraph.edgesPlusInlined.Length; ++i)
{
PatternEdge edge = patternGraph.edgesPlusInlined[i];
bool isPreset;
PlanNode planNode;
PlanEdge rootToNodePlanEdge;
CreatePlanNodeAndLookupPlanEdge(edge, i + 1,
graphStatistics, patternGraph, isNegativeOrIndependent, isSubpatternLike, planRoot, zeroCost,
originalToInlinedIndependent, presetsFromIndependentInlining,
out isPreset, out planNode, out rootToNodePlanEdge);
planNodes[nodesIndex] = planNode;
if(rootToNodePlanEdge != null)
{
planEdges.Add(rootToNodePlanEdge);
planNode.IncomingEdges.Add(rootToNodePlanEdge);
}
CreateSourceTargetIncomingOutgoingPlanEdges(edge, planNode, planEdges,
originalToInlinedIndependent, graphStatistics, patternGraph, isPreset, zeroCost);
edge.TempPlanMapping = planNode;
++nodesIndex;
}
if(InlineIndependents && !isNegativeOrIndependent) // independent inlining only if not in negative/independent
{
foreach(PatternGraph independent in patternGraph.independentPatternGraphsPlusInlined)
{
foreach(PatternEdge edgeOriginal in LGSPMatcherGenerator.EdgesInIndependentMatchedThere(independent))
{
PatternEdge edge = new PatternEdge(edgeOriginal, "_inlined_" + independent.name);
bool isPreset;
PlanNode planNode;
PlanEdge rootToNodePlanEdge;
CreatePlanNodeAndLookupPlanEdge(edge, -1,
graphStatistics, patternGraph, isNegativeOrIndependent, isSubpatternLike, planRoot, zeroCost,
originalToInlinedIndependent, presetsFromIndependentInlining,
out isPreset, out planNode, out rootToNodePlanEdge);
planNodes[nodesIndex] = planNode;
if(rootToNodePlanEdge != null)
{
planEdges.Add(rootToNodePlanEdge);
planNode.IncomingEdges.Add(rootToNodePlanEdge);
}
CreateSourceTargetIncomingOutgoingPlanEdges(edge, planNode, planEdges,
originalToInlinedIndependent, graphStatistics, patternGraph, isPreset, zeroCost);
edge.TempPlanMapping = planNode;
++nodesIndex;
}
}
}
////////////////////////////////////////////////////////////////////////////
// second run handling dependent storage and index picking (can't be done in first run due to dependencies between elements)
// create map/pick/cast/assign plan edges for all pattern graph nodes
for(int i = 0; i < patternGraph.nodesPlusInlined.Length; ++i)
{
PatternNode node = patternGraph.nodesPlusInlined[i];
if(node.PointOfDefinition == patternGraph && !presetsFromIndependentInlining.ContainsKey(node))
CreatePickMapCastAssignPlanEdges(node, planEdges, zeroCost);
}
// create map/pick/cast/assign plan edges for all pattern graph edges
for(int i = 0; i < patternGraph.edgesPlusInlined.Length; ++i)
{
PatternEdge edge = patternGraph.edgesPlusInlined[i];
if(edge.PointOfDefinition == patternGraph && !presetsFromIndependentInlining.ContainsKey(edge))
CreatePickMapCastAssignPlanEdges(edge, planEdges, zeroCost);
}
return new PlanGraph(planRoot, planNodes, planEdges.ToArray());
}
private void DumpNode(StreamWriter sw, PlanNode node)
{
if(node.NodeType == PlanNodeType.Edge)
sw.WriteLine("node:{{title:\"{0}\" label:\"{1} : {2}\" shape:ellipse}}",
GetDumpName(node), node.PatternElement.TypeID, node.PatternElement.Name);
else
sw.WriteLine("node:{{title:\"{0}\" label:\"{1} : {2}\"}}",
GetDumpName(node), node.PatternElement.TypeID, node.PatternElement.Name);
}
private String GetDumpName(PlanNode node)
{
if(node.NodeType == PlanNodeType.Root) return "root";
else if(node.NodeType == PlanNodeType.Node) return "node_" + node.PatternElement.Name;
else return "edge_" + node.PatternElement.Name;
}
public SearchPlanNodeNode(PlanNode planNode)
: base(planNode)
{
}
public SearchPlanEdgeNode(PlanNode planNode, SearchPlanNodeNode patEdgeSrc, SearchPlanNodeNode patEdgeTgt)
: base(planNode)
{
PatternEdgeSource = patEdgeSrc;
PatternEdgeTarget = patEdgeTgt;
}
private static void CreateSourceTargetIncomingOutgoingPlanEdges(PatternEdge edge, PlanNode planNode,
List<PlanEdge> planEdges, IDictionary<PatternNode, PatternNode> originalToInlinedIndependent,
PatternGraph patternGraph, bool isPreset, float zeroCost)
{
// only add implicit source operation if edge source is needed and the edge source is
// not a preset node and not a storage node and not an index node and not a cast node
PatternNode source = LGSPMatcherGenerator.GetSourcePlusInlined(edge, patternGraph, originalToInlinedIndependent);
if(source != null
&& !source.TempPlanMapping.IsPreset
&& source.Storage == null
&& source.IndexAccess == null
&& source.NameLookup == null
&& source.UniqueLookup == null
&& source.ElementBeforeCasting == null)
{
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.ImplicitSource : SearchOperationType.Implicit;
PlanEdge implSrcPlanEdge = new PlanEdge(operation, planNode,
source.TempPlanMapping, zeroCost);
planEdges.Add(implSrcPlanEdge);
source.TempPlanMapping.IncomingEdges.Add(implSrcPlanEdge);
}
// only add implicit target operation if edge target is needed and the edge target is
// not a preset node and not a storage node and not an index node and not a cast node
PatternNode target = LGSPMatcherGenerator.GetTargetPlusInlined(edge, patternGraph, originalToInlinedIndependent);
if(target != null
&& !target.TempPlanMapping.IsPreset
&& target.Storage == null
&& target.IndexAccess == null
&& target.NameLookup == null
&& target.UniqueLookup == null
&& target.ElementBeforeCasting == null)
{
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.ImplicitTarget : SearchOperationType.Implicit;
PlanEdge implTgtPlanEdge = new PlanEdge(operation, planNode,
target.TempPlanMapping, zeroCost);
planEdges.Add(implTgtPlanEdge);
target.TempPlanMapping.IncomingEdges.Add(implTgtPlanEdge);
}
// edge must only be reachable from other nodes if it's not a preset and not storage determined and not index determined and not a cast
if(!isPreset
&& edge.Storage == null
&& edge.IndexAccess == null
&& edge.NameLookup == null
&& edge.UniqueLookup == null
&& edge.ElementBeforeCasting == null)
{
float cost = (edge.Cost + 5.5f) / 2;
cost = LGSPMatcherGenerator.CostIncreaseForInlinedIndependent(edge, cost);
// no outgoing on source node if no source
if(source != null)
{
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.Outgoing : SearchOperationType.Incident;
PlanEdge outPlanEdge = new PlanEdge(operation, source.TempPlanMapping,
planNode, cost);
planEdges.Add(outPlanEdge);
planNode.IncomingEdges.Add(outPlanEdge);
}
// no incoming on target node if no target
if(target != null)
{
SearchOperationType operation = edge.fixedDirection ?
SearchOperationType.Incoming : SearchOperationType.Incident;
PlanEdge inPlanEdge = new PlanEdge(operation, target.TempPlanMapping,
planNode, cost);
planEdges.Add(inPlanEdge);
planNode.IncomingEdges.Add(inPlanEdge);
}
}
}
public PlanEdge[] Edges; // edges of the plan graph, representing search operations
public PlanGraph(PlanNode root, PlanNode[] nodes, PlanEdge[] edges)
{
Root = root;
Nodes = nodes;
Edges = edges;
}
public PlanEdge(SearchOperationType type, PlanNode source, PlanNode target, float cost)
{
Source = source;
Target = target;
Cost = cost;
mstCost = (float)Math.Max(Math.Log(cost), 1);
// mstCost = (float) Math.Max(Math.Log(cost), 0.0001);
// mstCost = cost;
Type = type;
}
/// <summary>
/// Instantiates an edge plan node.
/// </summary>
/// <param name="patEdge">The pattern edge for this plan node.</param>
/// <param name="elemID">The element ID for this plan node.</param>
/// <param name="isPreset">True, if this element is a known element.</param>
/// <param name="patternEdgeSource">The plan node corresponding to the source of the pattern edge.</param>
/// <param name="patternEdgeTarget">The plan node corresponding to the target of the pattern edge.</param>
public PlanNode(PatternEdge patEdge, int elemID, bool isPreset,
PlanNode patternEdgeSource, PlanNode patternEdgeTarget)
{
NodeType = PlanNodeType.Edge;
ElementID = elemID;
IsPreset = isPreset;
PatternElement = patEdge;
PatternEdgeSource = patternEdgeSource;
PatternEdgeTarget = patternEdgeTarget;
}