public override void Visit(WSelectQueryBlock node)
{
if (node.SelectElements == null || node.SelectElements.Count < 2)
{
throw new GraphViewException("Numbers of select elements mismatch.");
}
var sourceTableScalar = node.SelectElements[0] as WSelectScalarExpression;
if (sourceTableScalar == null)
throw new GraphViewException("Source node id should be a scalar expression.");
var sourceTableColumn = sourceTableScalar.SelectExpr as WColumnReferenceExpression;
if (sourceTableColumn == null)
throw new GraphViewException("Source node id column should be a column reference expression.");
var sourceTableName = sourceTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
var sourceNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sourceTableColumn.MultiPartIdentifier.Identifiers)
sourceNodeIdExpr.Add(identifier);
sourceNodeIdExpr.AddIdentifier("GlobalNodeId");
if (node.SelectElements.Count < 2)
throw new GraphViewException("Source and Sink tables should be specified in select elements.");
if (node.GroupByClause != null)
{
throw new GraphViewException("GROUP BY clause is not allowed in INSERT EDGE statement.");
}
var collectVarVisitor = new CollectVariableVisitor();
var context = collectVarVisitor.Invoke(node);
WColumnReferenceExpression sinkNodeIdExpr = null;
for (var index = 1; index < node.SelectElements.Count; ++index)
{
var element = node.SelectElements[index] as WSelectScalarExpression;
if (element == null)
throw new GraphViewException("Edge property should be a scalar expression.");
//sink table
if (index == 1)
{
var sinkTableColumn = element.SelectExpr as WColumnReferenceExpression;
if (sinkTableColumn == null)
throw new GraphViewException("Sink node id column should be a column reference expression.");
var sinkTableName = sinkTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
_sinkTable = context[sinkTableName];
sinkNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sinkTableColumn.MultiPartIdentifier.Identifiers)
sinkNodeIdExpr.Add(identifier);
sinkNodeIdExpr.AddIdentifier("GlobalNodeId");
}
else
{
_edgeProperties.Add(element.SelectExpr);
}
}
var sourceTable = context[sourceTableName] as WNamedTableReference;
if (sourceTable == null)
{
throw new GraphViewException("Source table of INSERT EDGE statement should be a named table reference.");
}
var sourceNodeId = new WSelectScalarExpression
{
SelectExpr = sourceNodeIdExpr,
ColumnName = "src",
};
var sinkNodeId = new WSelectScalarExpression
{
SelectExpr = sinkNodeIdExpr,
ColumnName = "sink"
};
var elements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId
};
var result = new WCommonTableExpression
{
ExpressionName = new Identifier {Value = _tempTableName},
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = new WWhereClause
{
SearchCondition = node.WhereClause.SearchCondition
},
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = elements,
MatchClause = node.MatchClause
}
};
_result = result;
}
private WCommonTableExpression ConstructDeleteEdgeSelect(WSelectQueryBlock node, string edgeAlias, string tempTableName
,out WTableReference sinkTable, out WTableReference sourceTable)
{
sourceTable = null;
sinkTable = null;
var sourceTableScalar = node.SelectElements[0] as WSelectScalarExpression;
if (sourceTableScalar == null)
return null;
var sourceTableColumn = sourceTableScalar.SelectExpr as WColumnReferenceExpression;
if (sourceTableColumn == null)
return null;
var sourceTableName = sourceTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
var sourceNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sourceTableColumn.MultiPartIdentifier.Identifiers)
sourceNodeIdExpr.Add(identifier);
sourceNodeIdExpr.AddIdentifier("GlobalNodeId");
var collectVarVisitor = new CollectVariableVisitor();
var context = collectVarVisitor.Invoke(node);
if (!context.NodeTableDictionary.Any())
{
throw new GraphViewException("Missing From Clause in Delete Edge statement");
}
WColumnReferenceExpression sinkNodeIdExpr = null;
sourceTable = context[sourceTableName];
var groupByParams = new List<WScalarExpression>();
for (var index = 1; index < node.SelectElements.Count; ++index)
{
var element = node.SelectElements[index] as WSelectScalarExpression;
if (element == null)
return null;
//sink table
if (index == 1)
{
var sinkTableColumn = element.SelectExpr as WColumnReferenceExpression;
if (sinkTableColumn == null)
return null;
var sinkTableName = sinkTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
sinkTable = context[sinkTableName];
sinkNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sinkTableColumn.MultiPartIdentifier.Identifiers)
sinkNodeIdExpr.Add(identifier);
sinkNodeIdExpr.AddIdentifier("GlobalNodeId");
}
}
var sourceNodeId = new WSelectScalarExpression
{
SelectExpr = sourceNodeIdExpr,
ColumnName = "src",
};
var sinkNodeId = new WSelectScalarExpression
{
SelectExpr = sinkNodeIdExpr,
ColumnName = "sink"
};
var edgeId = new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier[]
{
new Identifier {Value = edgeAlias},
new Identifier {Value = "Edgeid"}
}
)
},
ColumnName = "edgeid"
};
var elements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId,
edgeId
};
return new WCommonTableExpression
{
ExpressionName = new Identifier { Value = tempTableName },
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = new WWhereClause
{
SearchCondition = node.WhereClause.SearchCondition
},
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = elements,
MatchClause = node.MatchClause,
}
};
}
private WMultiCommonTableExpression ConstructDeleteEdgeSelect(WSelectQueryBlock node, WEdgeColumnReferenceExpression edgeCol, string tempTableName
,out WTableReference sinkTable, out WTableReference sourceTable, ref bool hasReversedEdge)
{
sourceTable = null;
sinkTable = null;
string sourceTableName = null;
string sinkTableName = null;
var sourceTableScalar = node.SelectElements[0] as WSelectScalarExpression;
if (sourceTableScalar == null)
return null;
var sourceTableColumn = sourceTableScalar.SelectExpr as WColumnReferenceExpression;
if (sourceTableColumn == null)
return null;
sourceTableName = sourceTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
var sourceNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sourceTableColumn.MultiPartIdentifier.Identifiers)
sourceNodeIdExpr.Add(identifier);
sourceNodeIdExpr.AddIdentifier("GlobalNodeId");
var collectVarVisitor = new CollectVariableVisitor();
var context = collectVarVisitor.Invoke(node);
if (!context.NodeTableDictionary.Any())
{
throw new GraphViewException("Missing From Clause in Delete Edge statement");
}
WColumnReferenceExpression sinkNodeIdExpr = null;
sourceTable = context[sourceTableName];
var groupByParams = new List<WScalarExpression>();
for (var index = 1; index < node.SelectElements.Count; ++index)
{
var element = node.SelectElements[index] as WSelectScalarExpression;
if (element == null)
return null;
//sink table
if (index == 1)
{
var sinkTableColumn = element.SelectExpr as WColumnReferenceExpression;
if (sinkTableColumn == null)
return null;
sinkTableName = sinkTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
sinkTable = context[sinkTableName];
sinkNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sinkTableColumn.MultiPartIdentifier.Identifiers)
sinkNodeIdExpr.Add(identifier);
sinkNodeIdExpr.AddIdentifier("GlobalNodeId");
}
}
var sourceNodeId = new WSelectScalarExpression
{
SelectExpr = sourceNodeIdExpr,
ColumnName = "src",
};
var sinkNodeId = new WSelectScalarExpression
{
SelectExpr = sinkNodeIdExpr,
ColumnName = "sink"
};
var edgeId = new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier[]
{
new Identifier {Value = edgeCol.Alias??string.Format("{0}_{1}_{2}",sourceTableName,edgeCol.MultiPartIdentifier.Identifiers.Last().Value,sinkTableName)},
new Identifier {Value = "Edgeid"}
})
},
ColumnName = "edgeid"
};
var sourceTableNameRef = sourceTable as WNamedTableReference;
if (sourceTableNameRef == null)
throw new GraphViewException("Source table of DELETE EDGE statement should be a named table reference.");
var sinkTableNameRef = sinkTable as WNamedTableReference;
if (sinkTableNameRef == null)
throw new GraphViewException("Sink table of DELETE EDGE statement should be a named table reference.");
int compare = string.CompareOrdinal(sourceTableNameRef.TableObjectName.ToString(), sinkTableNameRef.TableObjectName.ToString());
using (var command = Tx.Connection.CreateCommand())
{
command.Transaction = Tx;
command.Parameters.AddWithValue("@schema", WNamedTableReference.SchemaNameToTuple(sourceTableNameRef.TableObjectName).Item1);
command.Parameters.AddWithValue("@tableName", sourceTableNameRef.TableObjectName.Identifiers.Last().Value);
command.Parameters.AddWithValue("@colName", edgeCol.MultiPartIdentifier.Identifiers.Last().Value);
command.Parameters.AddWithValue("@role", WNodeTableColumnRole.Edge);
command.CommandText = string.Format(@"
SELECT NodeColumn.HasReversedEdge
FROM [{0}] AS NodeColumn
WHERE NodeColumn.TableSchema = @schema and
NodeColumn.TableName = @tableName and
NodeColumn.ColumnName = @colName and
NodeColumn.ColumnRole = @role",
GraphViewConnection.MetadataTables[1]);
using (var reader = command.ExecuteReader())
{
if (reader.Read())
{
hasReversedEdge = bool.Parse(reader[0].ToString());
}
}
}
var reversedEdgeName = sourceTableNameRef.TableObjectName.Identifiers.Last().Value +
"_" + edgeCol.MultiPartIdentifier.Identifiers.Last().Value + "Reversed";
var reversedEdgeId = new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier[]
{
new Identifier {Value = edgeCol.Alias??string.Format("{0}_{1}_{2}",sourceTableName,edgeCol.MultiPartIdentifier.Identifiers.Last().Value,sinkTableName)},
new Identifier {Value = "Edgeid"}
})
},
ColumnName = "edgeid"
};
var elements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId,
edgeId
};
var reversedElements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId,
reversedEdgeId,
};
return new WMultiCommonTableExpression
{
WCommonTableExpressions = new List<WCommonTableExpression>()
{
new WCommonTableExpression
{
ExpressionName = new Identifier
{
Value = hasReversedEdge && compare == 0 ? tempTableName + "_1" : tempTableName
},
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = new WWhereClause
{
SearchCondition = node.WhereClause.SearchCondition
},
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = elements,
MatchClause = node.MatchClause,
}
},
new WCommonTableExpression
{
ExpressionName = new Identifier
{
Value = hasReversedEdge && compare == 0 ? tempTableName + "_2" : tempTableName
},
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = hasReversedEdge ?
new WWhereClause { SearchCondition = ObjectExtensions.Copy(node.WhereClause.SearchCondition), }
: node.WhereClause,
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = hasReversedEdge ? reversedElements : elements,
MatchClause = hasReversedEdge? ConstructReversedMatchClause(node, context) : node.MatchClause,
}
},
}
};
}
/// <summary>
/// The entry point of the optimizer, activated when visting each SELECT query block.
/// </summary>
/// <param name="node">The SELECT query block</param>
public override void Visit(WSelectQueryBlock node)
{
var checkVarVisitor = new CollectVariableVisitor();
var currentContext = checkVarVisitor.Invoke(node.FromClause, _graphMetaData.ColumnsOfNodeTables.Keys);
currentContext.ParentContext = _context;
_context = currentContext;
base.Visit(node);
CheckValidity(node);
var graph = ConstructGraph(node);
//ChangeSelectStarExpression(node, graph);
if (graph != null)
{
//OptimizeTail(node, graph);
AttachPredicates(node.WhereClause,graph);
EstimateRows(graph);
RetrieveStatistics(graph);
var components = new List<MatchComponent>();
foreach (var subGraph in graph.ConnectedSubGraphs)
{
components.Add(ConstructComponent(subGraph, graph.ReversedEdgeDict, graph.SourceNodeStatisticsDict));
#if DEBUG
foreach (var matchNode in subGraph.Nodes.Values)
{
Trace.WriteLine(matchNode.NodeAlias);
Trace.WriteLine(string.Format(" RowCount:{0}", matchNode.TableRowCount));
Trace.WriteLine(string.Format(" EstiRow:{0}", matchNode.EstimatedRows));
}
#endif
}
UpdateQuery(node, components);
#if DEBUG
Trace.WriteLine(string.Format("Rows:{0}", components[0].Cardinality));
Trace.WriteLine(string.Format("Cost:{0}", components[0].Cost));
Trace.WriteLine(string.Format("Estimated Rows:{0}", components[0].SqlEstimatedSize));
#endif
node.MatchClause = null;
}
_context = _context.ParentContext;
}
/// <summary>
/// The entry of the optimizer, activated when visting each Select Query Block
/// </summary>
/// <param name="node"></param>
public override void Visit(WSelectQueryBlock node)
{
var checkVarVisitor = new CollectVariableVisitor();
var currentContext = checkVarVisitor.Invoke(node.FromClause, _columnsOfNodeTables.Keys);
currentContext.UpperLevel = _context;
_context = currentContext;
base.Visit(node);
_statisticsCalculator.Context = _context;
CheckValidity(node);
var graph = ConstructGraph(node);
//ChangeSelectStarExpression(node, graph);
if (graph != null)
{
OptimizeTail(node, graph);
EstimateRows(node, graph);
EstimateAverageDegree(graph);
var components = new List<MatchComponent>();
foreach (var subGraph in graph.ConnectedSubGraphs)
{
components.Add(ConstructComponent(subGraph));
#if DEBUG
foreach (var matchNode in subGraph.Nodes.Values)
{
Trace.WriteLine(matchNode.NodeAlias);
Trace.WriteLine(string.Format(" RowCount:{0}", matchNode.TableRowCount));
Trace.WriteLine(string.Format(" EstiRow:{0}", matchNode.EstimatedRows));
}
#endif
}
UpdateQuery(node, components);
#if DEBUG
Trace.WriteLine(string.Format("Rows:{0}", components[0].Size));
Trace.WriteLine(string.Format("Cost:{0}", components[0].Cost));
Trace.WriteLine(string.Format("Estimated Rows:{0}", components[0].EstimateSize));
#endif
node.MatchClause = null;
}
_context = _context.UpperLevel;
}