@API(value=EXPERIMENTAL) public interface QueryPredicate extends Bindable, PlanHashable
SourceEntry (usually derived from a record).
QueryPredicate is generally quite similar to QueryComponent.
However, there is a key difference in how each interface evaluates the predicate against a given record:
QueryComponent is evaluated on a
FDBRecord wrapping a Protobuf message.
To evaluate predicates on nested records, a QueryComponent such as
NestedField or
OneOfThemWithComponent will descend into the nested
record.
QueryPredicate is evaluated on a SourceEntry, which maps
Sources to values. The predicate can be evaluated
on a nested record by specifying a complex Source, such as
RepeatedFieldSource. All sources are evaluated
to produce a stream of source entries before any predicates are evaluated.
Concretely, the difference between QueryPredicates and QueryComponents is most easily seen in the
way that multiple predicates on repeated fields can be expressed. Any query predicate anywhere in a tree of
predicates can make use of any source. In contrast, each OneOfThemWithComponent
is a single iteration through the field's repeated values so the values obtained by that iteration are usable only
within that OneOfThemWithComponent.
| Modifier and Type | Method and Description |
|---|---|
<M extends Message> |
eval(FDBRecordStoreBase<M> store,
EvaluationContext context,
SourceEntry sourceEntry) |
combineHashes, iterablePlanHash, objectPlanHash, objectsPlanHash, planHash, planHash, planHash, planHashUnordered, stringHashUnordered@Nullable <M extends Message> Boolean eval(@Nonnull FDBRecordStoreBase<M> store, @Nonnull EvaluationContext context, @Nonnull SourceEntry sourceEntry)