//private PhysicalOperation FindIndexes(SelectionElement selectionElement)
//{
// List<LeafCondition> leafs = GetLeafConditions(selectionElement.Condition);
// foreach(LeafCondition leaf in leafs)
// {
// if (leaf.Column.Relation is TableDefinition tableDefinition)
// {
// Index index = tableDefinition.Indexes.FirstOrDefault(x => string.Equals(x.Column, leaf.Column.Name, StringComparison.OrdinalIgnoreCase));
// if (index != null)
// {
// ;
// }
// }
// }
// if (leafs.Count == 0)
// {
// // index seek / table scan
// return GetFullTableScanOperation(selectionElement..)
// }
//}
public PhysicalOperation GetPhysicalPlan(LogicalElement logicalTree)
{
List <LogicalElement> postorderLogicalTree = AppendPostOrder(new List <LogicalElement>(), logicalTree);
QueryPlanNode root = new QueryPlanNode(null, null);
List <QueryPlanNode> lastOptions = new List <QueryPlanNode> {
root
};
for (int i = 0; i < postorderLogicalTree.Count; i++)
{
LogicalElement element = postorderLogicalTree[i];
Dictionary <QueryPlanNode, int> options = GetOptions(element);
ConnectEndNodesToNodes(lastOptions, options);
lastOptions = options.Select(x => x.Key).ToList();
}
List <QueryPlanNode> leastCostPath = GetLeastCostPath(root);
PhysicalOperation physicalOperation = CreateFromPath(logicalTree, leastCostPath);
return(physicalOperation);
}
private void ApplyInputOperations(LogicalElement logicalTree, List <QueryPlanNode> path)
{
if (logicalTree == null)
{
return;
}
PhysicalOperation curNode = path.First(x => x.LogicalElement == logicalTree).PhysicalOperation;
PhysicalOperation leftInput = null;
if (logicalTree.LeftChild != null)
{
leftInput = path.First(x => x.LogicalElement == logicalTree.LeftChild).PhysicalOperation;
}
PhysicalOperation rightInput = null;
if (logicalTree.RightChild != null)
{
rightInput = path.First(x => x.LogicalElement == logicalTree.RightChild).PhysicalOperation;
}
curNode?.SetInput(leftInput, rightInput);
ApplyInputOperations(logicalTree.LeftChild, path);
ApplyInputOperations(logicalTree.RightChild, path);
}
public HashSetJoinOperation(LogicalElement logicalElement, PhysicalOperation left, PhysicalOperation right, AttributeDefinition leftJoinColumn, AttributeDefinition rightJoinColumn)
: base(logicalElement)
{
Left = left;
Right = right;
_leftJoinColumn = leftJoinColumn;
_rightJoinColumn = rightJoinColumn;
}
public void SetInput(PhysicalOperation left, PhysicalOperation right)
{
Left = left;
Right = right;
}
public TopOperation(LogicalElement logicalElement, PhysicalOperation inputOperation, int?amount)
: base(logicalElement)
{
Left = inputOperation;
_amount = amount;
}
public UnionOperator(LogicalElement logicalElement, PhysicalOperation left, PhysicalOperation right)
: base(logicalElement)
{
Left = left;
Right = right;
}
private Dictionary <QueryPlanNode, int> GetOptions(LogicalElement element)
{
Dictionary <QueryPlanNode, int> options = new Dictionary <QueryPlanNode, int>();
if (element is ProjectionElement p)
{
PhysicalOperation proj = new ProjectionOperation(element, null, p.Columns.Select(x => x.AttributeDefinition).ToList());
options.Add(new QueryPlanNode(element, proj), proj.GetCost());
}
else if (element is SelectionElement selectionElement)
{
if (selectionElement.LeftChild is RelationElement relationElement)
{
Table table = Program.RelationManager.GetTable(relationElement.Relation.Id);
PhysicalOperation tableScan = new TableScanOperation(element, table);
if (selectionElement.Condition != null)
{
PhysicalOperation f = new FilterOperation(element, tableScan, selectionElement.Condition);
options.Add(new QueryPlanNode(element, f), f.GetCost());
}
else
{
options.Add(new QueryPlanNode(element, tableScan), tableScan.GetCost());
}
Condition clonedCondition = selectionElement.Condition?.Clone();
if (TryExtractConstantConditionWithIndex(relationElement.Relation, clonedCondition, out LeafCondition constantCondition))
{
selectionElement.Condition = selectionElement.Condition.Simplify();
PhysicalOperation indexSeek = new IndexSeekOperation(element, table, table.GetIndex(table.TableDefinition.GetClusteredIndex().Column), constantCondition);
if (selectionElement.Condition != null)
{
PhysicalOperation f = new FilterOperation(element, indexSeek, clonedCondition);
options.Add(new QueryPlanNode(element, f), f.GetCost());
}
else
{
options.Add(new QueryPlanNode(element, indexSeek), indexSeek.GetCost());
}
}
else
{
if (table.TableDefinition.HasClusteredIndex())
{
PhysicalOperation indexSeek = new IndexSeekOperation(element, table, table.GetIndex(table.TableDefinition.GetClusteredIndex().Column), constantCondition);
if (selectionElement.Condition != null)
{
PhysicalOperation f = new FilterOperation(element, indexSeek, selectionElement.Condition);
options.Add(new QueryPlanNode(element, f), f.GetCost());
}
else
{
options.Add(new QueryPlanNode(element, indexSeek), indexSeek.GetCost());
}
}
}
}
}
else if (element is RelationElement relElement)
{
Table table = Program.RelationManager.GetTable(relElement.Relation.Id);
if (table.TableDefinition.HasClusteredIndex())
{
PhysicalOperation indexSeek = new IndexScanOperation(element, table, table.GetIndex(table.TableDefinition.GetClusteredIndex().Column));
options.Add(new QueryPlanNode(element, indexSeek), indexSeek.GetCost());
}
PhysicalOperation tableScan = new TableScanOperation(element, table);
options.Add(new QueryPlanNode(element, tableScan), tableScan.GetCost());
}
else if (element is CartesianProductElement cartesianProduct)
{
PhysicalOperation left = null; //GetDefaultPhysicalOperation(element.LeftChild);
PhysicalOperation right = null; //GetDefaultPhysicalOperation(element.RightChild);
PhysicalOperation join = new NestedLoopJoinOperation(cartesianProduct, (ReadLogicalElement)element.LeftChild, (ReadLogicalElement)element.RightChild, cartesianProduct.LeftJoinColumn, cartesianProduct.RightJoinColumn);
options.Add(new QueryPlanNode(cartesianProduct, join), join.GetCost());
}
else if (element is MemorySetElement memElem)
{
options.Add(new QueryPlanNode(memElem, new MemorySetOperation(memElem, memElem.Set)), 0);
}
else if (element is InsertElement insertElem)
{
Table table = Program.RelationManager.GetTable(insertElem.TableDefinition.Id);
options.Add(new QueryPlanNode(insertElem, new InsertOperation(insertElem, table)), 0);
}
if (options.Count == 0)
{
throw new Exception();
}
return(options);
}
public ProjectionOperation(LogicalElement logicalElement, PhysicalOperation inputOperation, List <AttributeDefinition> projectionColumns)
: base(logicalElement)
{
Left = inputOperation;
_projectionColumns = projectionColumns;
}
public FilterOperation(LogicalElement logicalElement, PhysicalOperation inputOperation, Condition condition)
: base(logicalElement)
{
Left = inputOperation;
Condition = condition;
}
