Deveel.Data.Sql.Query.QueryTablePlanner.StandardJoinPlan Class Reference

Inheritance diagram for Deveel.Data.Sql.Query.QueryTablePlanner.StandardJoinPlan:

Public Member Functions
	StandardJoinPlan (QueryTablePlanner planner, SqlBinaryExpression expression, float optimizeFactor)
override void	AddToPlanTree ()
Public Member Functions inherited from Deveel.Data.Sql.Query.QueryTablePlanner.ExpressionPlan
int	CompareTo (IExpressionPlan other)

Private Attributes
readonly QueryTablePlanner	planner
readonly SqlBinaryExpression	expression

Additional Inherited Members
Protected Member Functions inherited from Deveel.Data.Sql.Query.QueryTablePlanner.ExpressionPlan
	ExpressionPlan (float optimizeFactor)
Properties inherited from Deveel.Data.Sql.Query.QueryTablePlanner.ExpressionPlan
float	OptimizeFactor [get, private set]
Properties inherited from Deveel.Data.Sql.Query.IExpressionPlan
float	OptimizeFactor [get]

Detailed Description

Definition at line 1049 of file QueryTablePlanner.cs.

Constructor & Destructor Documentation

Deveel.Data.Sql.Query.QueryTablePlanner.StandardJoinPlan.StandardJoinPlan ( QueryTablePlanner  planner, SqlBinaryExpression  expression, float  optimizeFactor  )

inline

Definition at line 1053 of file QueryTablePlanner.cs.

                : base(optimizeFactor) {
                this.planner = planner;
                this.expression = expression;
            }

Member Function Documentation

override void Deveel.Data.Sql.Query.QueryTablePlanner.StandardJoinPlan.AddToPlanTree ( )

inlinevirtual

Implements Deveel.Data.Sql.Query.QueryTablePlanner.ExpressionPlan.

Definition at line 1059 of file QueryTablePlanner.cs.

                                                 {
                var op = expression.ExpressionType;
                var lhsVar = expression.Left.AsReferenceName();
                var rhsVar = expression.Right.AsReferenceName();
                var lhsVars = expression.Left.DiscoverReferences();
                var rhsVars = expression.Right.DiscoverReferences();

                var lhsPlan = planner.JoinPlansForColumns(lhsVars);
                var rhsPlan = planner.JoinPlansForColumns(rhsVars);

                if (lhsPlan != rhsPlan) {
                    // If either the LHS or the RHS is a single column then we can
                    // optimize the join.

                    if (lhsVar != null || rhsVar != null) {
                        // If right column is a single and left column is not then we must
                        // reverse the expression.
                        JoinNode joinNode;
                        if (lhsVar == null) {
                            // Reverse the expressions and the operator
                            joinNode = new JoinNode(rhsPlan.Plan, lhsPlan.Plan, rhsVar, op.Reverse(), expression.Left);
                            planner.MergePlans(rhsPlan, lhsPlan, joinNode);
                        } else {
                            // Otherwise, use it as it is.
                            joinNode = new JoinNode(lhsPlan.Plan, rhsPlan.Plan, lhsVar, op, expression.Right);
                            planner.MergePlans(lhsPlan, rhsPlan, joinNode);
                        }

                        // Return because we are done
                        return;
                    }
                }

                // If we get here either both the lhs and rhs are complex expressions
                // or the lhs and rhs of the variable are not different plans, or
                // the operator is not a conditional.  Either way, we must evaluate
                // this via a natural join of the variables involved coupled with an
                // exhaustive select.  These types of queries are poor performing.

                var columnNames = expression.DiscoverReferences();
                var tablePlan = planner.JoinPlansForColumns(columnNames);
                tablePlan.UpdatePlan(new ExhaustiveSelectNode(tablePlan.Plan, expression));
            }

Member Data Documentation

readonly SqlBinaryExpression Deveel.Data.Sql.Query.QueryTablePlanner.StandardJoinPlan.expression

private

Definition at line 1051 of file QueryTablePlanner.cs.

readonly QueryTablePlanner Deveel.Data.Sql.Query.QueryTablePlanner.StandardJoinPlan.planner

private

Definition at line 1050 of file QueryTablePlanner.cs.

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The documentation for this class was generated from the following file:

• /var/calculate/remote/distfiles/egit-src/deveeldb.git/src/deveeldb/Deveel.Data.Sql.Query/QueryTablePlanner.cs