com.apple.foundationdb.record.metadata (fdb-record-layer-core 2.8.97.0 API)

Interface Summary
Interface	Description
IndexValidatorRegistry	A registry of `IndexValidator`s.
RecordTypeOrBuilder	Common interface implemented by the `RecordType` and `RecordTypeBuilder` classes that contains accessors that they are both expected to have.

Class Summary
Class	Description
FormerIndex	The location where a deleted index used to live.
Index	Meta-data for a secondary index.
IndexAggregateFunction	An aggregate function implemented by scanning an appropriate index.
IndexOptions	The standard options for use with `Index`.
IndexRecordFunction<T>	A function which is applied to a record with the help of an index.
IndexTypes	The standard index types.
IndexValidator	Validate an index according to the constraints of the index's type.
JoinedRecordType	A synthetic record type representing the indexable result of joining stored records.
JoinedRecordType.Join	An equi-join between constituent types.
JoinedRecordType.JoinConstituent	A constituent type within a joined record type.
JoinedRecordTypeBuilder	A builder for `JoinedRecordType`.
JoinedRecordTypeBuilder.Join	An equi-join between constituent types.
JoinedRecordTypeBuilder.JoinConstituent	A constituent type within a joined record type.
Key	Namespace for classes related to `KeyExpression` construction and evaluation.
Key.Evaluated	Represents the list objects for a key in a secondary index or primary storage.
Key.Expressions	Holder class for the static methods for creating Key Expressions.
MetaDataEvolutionValidator	This class can be used to validate that the new meta-data for a record store is responsibly evolved from its existing meta-data.
MetaDataEvolutionValidator.Builder	A builder class for the `MetaDataEvolutionValidator`.
MetaDataValidator	Validator for `RecordMetaData`.
RecordType	Record type meta-data.
RecordTypeBuilder	A builder for `RecordType`.
RecordTypeIndexesBuilder	A base builder for `RecordType`.
StoreRecordFunction<T>	Record function that should be evaluated for some record against an `FDBRecordStoreBase` instance.
SyntheticRecordType<C extends SyntheticRecordType.Constituent>	A synthetic record type is made up of other record types and not actually stored separately in the record store.
SyntheticRecordType.Constituent	A constituent type of the synthetic record type.
SyntheticRecordTypeBuilder<C extends SyntheticRecordTypeBuilder.Constituent>	A builder for `SyntheticRecordType`.
SyntheticRecordTypeBuilder.Constituent	A constituent type within a joined record type.

Enum Summary
Enum Description

Key.Evaluated.NullStandin
Values used in index keys in place of missing fields.

Enum Summary
Enum	Description
Key.Evaluated.NullStandin	Values used in index keys in place of missing fields.

Exception Summary
Exception	Description
MetaDataException	Exception thrown when there is a problem with something in the `RecordMetaDataProto.MetaData`.
RecordTypeBuilder.NonbuildableException	Exception thrown when a `RecordTypeBuilder` is not yet in a state where it can be built.

Package com.apple.foundationdb.record.metadata Description

Record meta-data structures.

Record Layer Meta-Data

All operations on records are mediated by a RecordMetaData. It describes the format of persistent records, their fields and secondary indexes. There is a rough correspondence between the terminology used within the Record Layer and those used by relational databases:

relational correspondences
Record Layer	Relational
meta-data	schema
record type	table
field	column

Note that this correspondence is not exact. In particular, note that a record type and a table differ in that records of various types are included within the same extent. There are more details about the differences between tables and record types within the Record Layer FAQ.

The core of the meta-data is a Protobuf Descriptors.FileDescriptor. Every RecordType corresponds to a message Descriptors.Descriptor in the file descriptor. The possible fields of the record are the fields of the message.

A RecordMetaDataBuilder is used to construct meta-data from a file descriptor or to restore serialized meta-data from the database. A RecordTypeBuilder is used to specify options for a record type. In particular, a record type has a primary key and any number of secondary Indexes. The fields of the primary key and of an index are specified by a KeyExpression.