Package org.apache.tinkerpop.gremlin.gql

Class GqlMatchPlan

java.lang.Object

org.apache.tinkerpop.gremlin.gql.GqlMatchPlan

public final class GqlMatchPlan
extends Object

The compiled physical execution plan for a GQL MATCH query. A GqlMatchPlan is an ordered sequence of ExtensionStep objects produced by the TinkerGraphGqlPlanner from a QueryGraph.

The planner selects a seed vertex (lowest-cardinality anchor) and emits one ExtensionStep per edge in the QueryGraph, ordered so each step's anchor variable is bound before the step executes. The executor iterates these steps to perform DFS backtracking pattern matching.

The seed node is described by getSeedVariable(), getSeedLabel(), and getSeedPredicates(). The executor binds the seed variable first (iterating all vertices matching the seed label and property predicates) before processing the extension steps.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ANON_VAR_PREFIX	Prefix used for synthetic variable names assigned to anonymous pattern nodes/edges (those written without an explicit variable, e.g.

Constructor Summary

Constructors

Constructor	Description
GqlMatchPlan(String seedVariable, String seedLabel, List<ExtensionStep> steps, Map<String,Integer> variableIndex, String[] variables)
GqlMatchPlan(String seedVariable, String seedLabel, List<ExtensionStep> steps, Map<String,Integer> variableIndex, String[] variables, List<PropertyPredicate> seedPredicates)

Method Summary

Modifier and Type	Method	Description
int	getIndex(String variableName)	Returns the binding-array index for the given variable name.
String	getSeedLabel()	Returns the label constraint of the seed node, or null if unconstrained.
List<PropertyPredicate>	getSeedPredicates()	Returns property equality predicates on the seed node derived from its inline filter map.
String	getSeedVariable()	Returns the effective variable name of the seed node.
int	getSeedVariableIndex()	Returns the index of the seed variable in the binding array.
List<ExtensionStep>	getSteps()	Returns the ordered list of extension steps that the executor will process.
int	getVariableCount()	Returns the total number of variables (= binding array length).
String[]	getVariables()	Returns the variable name at each binding-array index.
boolean	isEmpty()	Returns true if the plan has no steps (e.g., a single-node pattern with no edges).
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

ANON_VAR_PREFIX

public static final String ANON_VAR_PREFIX

Prefix used for synthetic variable names assigned to anonymous pattern nodes/edges (those written without an explicit variable, e.g. ()-[:knows]->() ). Variables with this prefix are internal bookkeeping and are never exposed in result binding maps or traverser paths.

See Also:

• Constant Field Values

Constructor Details

GqlMatchPlan

public GqlMatchPlan(String seedVariable,
 String seedLabel,
 List<ExtensionStep> steps,
 Map<String,Integer> variableIndex,
 String[] variables,
 List<PropertyPredicate> seedPredicates)

GqlMatchPlan

public GqlMatchPlan(String seedVariable,
 String seedLabel,
 List<ExtensionStep> steps,
 Map<String,Integer> variableIndex,
 String[] variables)

Method Details

getSeedVariable

public String getSeedVariable()

Returns the effective variable name of the seed node. May be a synthetic name (prefixed with $anon) if the seed node has no explicit variable.

getSeedLabel

public String getSeedLabel()

Returns the label constraint of the seed node, or null if unconstrained.

getSeedPredicates

public List<PropertyPredicate> getSeedPredicates()

Returns property equality predicates on the seed node derived from its inline filter map. The executor applies these when iterating seed candidates. Empty if no filter was specified on the seed node.

getSteps

public List<ExtensionStep> getSteps()

Returns the ordered list of extension steps that the executor will process.

getSeedVariableIndex

public int getSeedVariableIndex()

Returns the index of the seed variable in the binding array. Always 0.

getIndex

public int getIndex(String variableName)

Returns the binding-array index for the given variable name.

getVariableCount

public int getVariableCount()

Returns the total number of variables (= binding array length).

getVariables

public String[] getVariables()

Returns the variable name at each binding-array index. Used by TinkerGraphMatchStep to iterate result rows by index.

isEmpty

public boolean isEmpty()

Returns true if the plan has no steps (e.g., a single-node pattern with no edges).

toString

public String toString()

Overrides:

toString in class Object