module FDB
module FDB::FDBC
module FDB::Internal
module FDB::Locality
module FDB::Tuple
class FDB::AllocatorTransactionState
class FDB::CallbackEntry
class FDB::Cluster
class FDB::ClusterOptions
class FDB::Database
class FDB::DirectoryLayer
class FDB::DirectoryPartition
class FDB::DirectorySubspace
class FDB::Error
class FDB::FDBC::KeyStruct
class FDB::FDBC::KeyValueStruct
class FDB::FormerFuture
class FDB::Future
class FDB::FutureKeyArray
class FDB::FutureKeyValueArray
class FDB::FutureNil
class FDB::FutureStringArray
class FDB::HighContentionAllocator
class FDB::Int64Future
class FDB::Internal::Node
class FDB::Key
class FDB::KeySelector
class FDB::KeyValue
class FDB::LazyFuture
class FDB::LazyString
class FDB::Subspace
class FDB::Transaction
class FDB::TransactionRead
class FDB::Tuple::SingleFloat
class FDB::Tuple::UUID
class FDB::Value
fdb
7.3.72
# prefetch_metadata
def prefetch_metadata(tr) layer(tr) if exists? self end