protected override BoundRelation RewriteTableRelation(BoundTableRelation node)
{
var symbol = node.TableInstance.Table as CommonTableExpressionSymbol;
if (symbol == null)
{
return(base.RewriteTableRelation(node));
}
if (IsInstantiatedCommonTableExpression(node))
{
return(new BoundConstantRelation());
}
var outputValues = node.GetOutputValues().ToImmutableArray();
var instantiatedQuery = symbol.RecursiveMembers.Any()
? InstantiateRecursiveCommonTableExpression(outputValues, symbol)
: InstantiateCommonTableExpression(outputValues, symbol);
// For regular SELECT queries the output node will be a projection.
// We don't need this moving forward so it's safe to omit.
//
// NOTE: We need to keep this after we added the output slot mapping.
// Otherwise the slots will not align.
var projection = instantiatedQuery as BoundProjectRelation;
var result = projection == null ? instantiatedQuery : projection.Input;
return(result);
}
protected override BoundRelation RewriteTableRelation(BoundTableRelation node)
{
var definedValues = RemoveUnusedSlots(node.DefinedValues, d => d.ValueSlot);
node = node.Update(node.TableInstance, definedValues);
return(base.RewriteTableRelation(node));
}
protected override void VisitTableRelation(BoundTableRelation node)
{
if (node.TableInstance.Table == _symbol)
{
Debug.Assert(_instance == null);
_instance = node.TableInstance;
}
base.VisitTableRelation(node);
}
private static ShowPlanNode BuildTable(BoundTableRelation node)
{
var properties = Enumerable.Empty <KeyValuePair <string, string> >();
var children = Enumerable.Empty <ShowPlanNode>();
var name = node.TableInstance.Table.Name;
var columns = string.Join(@", ", node.DefinedValues.Select(d => d.ValueSlot.Name));
return(new ShowPlanNode($"Table ({name}), DefinedValues := {columns}", properties, children));
}
private static Iterator BuildTable(BoundTableRelation relation)
{
var schemaTableSymbol = (SchemaTableSymbol)relation.TableInstance.Table;
var tableDefinition = schemaTableSymbol.Definition;
var columnInstances = relation.DefinedValues;
var definedValues = columnInstances.Select(ci => ci.Column)
.Cast <SchemaColumnSymbol>()
.Select(c => BuildColumnAccess(c.Definition));
return(new TableIterator(tableDefinition, definedValues));
}
protected override BoundRelation RewriteTableRelation(BoundTableRelation node)
{
if (!node.DefinedValues.Any())
{
return(node);
}
var factory = node.DefinedValues.First().ValueSlot.Factory;
var original = node.TableInstance;
var valueSlotMapping = original.ColumnInstances.ToDictionary(c => c.Column, c => _valueSlotMapping[c.ValueSlot]);
var instanceName = factory.CreateNamed(original.Name, typeof(int)).Name;
var instance = new TableInstanceSymbol(instanceName, original.Table, (t, c) => valueSlotMapping[c]);
var columnMapping = instance.ColumnInstances.ToDictionary(c => c.Column);
var definedValues = node.DefinedValues.Select(d => columnMapping[d.Column]).ToImmutableArray();
return(node.Update(instance, definedValues));
}
private static CardinalityEstimate EstimateTableRelation(BoundTableRelation relation)
{
var tableSymbol = relation.TableInstance.Table as SchemaTableSymbol;
if (tableSymbol == null)
{
return(CardinalityEstimate.Unknown);
}
var collection = tableSymbol.Definition.GetRows() as ICollection;
if (collection == null)
{
return(CardinalityEstimate.Unknown);
}
return(new CardinalityEstimate(0, collection.Count));
}
