Module com.darkcollective.relix.symbol

Package com.darkcollective.relix.symbol.graph

Interface JoinResolution

All Known Implementing Classes:

JoinResolution.Ambiguous, JoinResolution.Passthrough, JoinResolution.Resolved

public sealed interface JoinResolution
permits JoinResolution.Passthrough, JoinResolution.Resolved, JoinResolution.Ambiguous

What resolving the joins in an expression over a SchemaGraph came to: the engine's own assembly of the join from the relationships the graph records, rather than the conditions the expression was written with. One of three shapes:

• JoinResolution.Passthrough — the graph adds nothing decidable (no graph, fewer than two graph relations, a disconnected or intractable expression), so the expression stands as written. Carries a reason.
• JoinResolution.Resolved — a unique minimal path; the join was rewritten over the graph's conditions (program), with the multiplicity JoinResolution.BoundsFacts of that path.
• JoinResolution.Ambiguous — several equally minimal paths (two foreign keys from issues into users, say), which the engine cannot choose between, so it lists the JoinResolution.Alternatives by relationship name.

Since:

1.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static final record	JoinResolution.Alternative	One enumerated join, distinguished by relationship name — the ambiguity is speakable only because edges are named.
static final record	JoinResolution.Ambiguous	Several equally minimal paths; each JoinResolution.Alternative is a runnable program.
static final record	JoinResolution.BoundsFacts	Multiplicity facts of a chosen path: whether the join fans out (an endpoint admits more than one match, repeating rows) and whether an inner join may drop rows (an endpoint's min is zero).
static final record	JoinResolution.Passthrough	The graph could not improve on the model's program; it stands unchanged.
static final record	JoinResolution.Resolved	A unique path was assembled into program with its bounds.