Class IndexAttribute
- Namespace
- Typhon.Schema.Definition
- Assembly
- Typhon.Schema.Definition.dll
Marks a component field for indexing, maintaining a B+Tree index over the field's values for lookups and range scans.
[AttributeUsage(AttributeTargets.Field)]
public sealed class IndexAttribute : Attribute- Inheritance
-
IndexAttribute
- Inherited Members
Constructors
IndexAttribute()
public IndexAttribute()Properties
AllowMultiple
true for a non-unique index (many entities may share a key value); false (default) for a unique index (one entity per key).
public bool AllowMultiple { get; set; }Property Value
OnParentDelete
Cascade action when the parent entity (referenced by an EntityLink<T> FK field) is deleted.
Only applicable to indexed EntityLink fields. Default is None.
public CascadeAction OnParentDelete { get; set; }Property Value
Sparse
true for a sparse index: an entity whose key is 0 — "no data", the engine's rule for an optional value — is not indexed at all, so an
index over a field most entities leave at 0 costs only the entities that set it. A query whose range admits 0 is answered from the data, never the
tree; the raw index enumeration never yields key 0. A unique sparse index lets any number of entities hold 0. Integer key types only (byte, short,
int, long, their unsigned forms, and char).
public bool Sparse { get; set; }