gudusoft.gsqlparser.ir.semantic.diff

Class CanonicalLineageEdge

Object

gudusoft.gsqlparser.ir.semantic.diff.CanonicalLineageEdge

public final class CanonicalLineageEdge
extends Object

One canonical-form lineage edge used for cross-engine comparison.

Identity is over four fields:

• role — EdgeRole.
• outputName — the outer-query output column the edge belongs to. Always non-null for EdgeRole.SELECT; always null for EdgeRole.FILTER and EdgeRole.JOIN. The null-anchor is what makes the SELECT and FILTER/JOIN sets disjoint by construction without a string sentinel that could collide with a legitimate alias (see slice-7 plan, "Row-influence: typed null-output anchor").
• baseTable — resolved base-table qualified name (lower-cased).
• baseColumn — column on that base table (lower-cased).

Aggregate-ness is not part of edge identity — it lives in CanonicalLineageModel.getAggregateByOutput(). Encoding it on the edge would mean COUNT(*) outputs (which produce zero edges) could vanish entirely from the model, and would break Java equality semantics for sets of edges.

Field Summary

Fields

Modifier and Type	Field and Description
static Comparator<CanonicalLineageEdge>	ORDER Total ordering used everywhere a deterministic edge sequence is needed.

Constructor Summary

Constructors

Constructor and Description
CanonicalLineageEdge(EdgeRole role, String outputName, String baseTable, String baseColumn)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
String	getBaseColumn()
String	getBaseTable()
String	getOutputName() Non-null for SELECT, null for FILTER/JOIN.
EdgeRole	getRole()
int	hashCode()
String	toString()

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ORDER

public static final Comparator<CanonicalLineageEdge> ORDER

Total ordering used everywhere a deterministic edge sequence is needed.

Constructor Detail

CanonicalLineageEdge

public CanonicalLineageEdge(EdgeRole role,
                            String outputName,
                            String baseTable,
                            String baseColumn)

Method Detail

getRole

public EdgeRole getRole()

getOutputName

public String getOutputName()

Non-null for SELECT, null for FILTER/JOIN.

getBaseTable

public String getBaseTable()

getBaseColumn

public String getBaseColumn()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object