NDB Cluster Configuration Files of number of records ( BatchSize ) and in terms of bytes ( BatchByteSize ). The actual batch size is limited by both parameters. The speed at which queries are performed can vary by more than 40% depending upon how this parameter is set. This parameter is measured in bytes. The default value is 16K. • BatchSize Version (or later) NDB 8.0.13 Type or units records Default 256 Range 1 - 992 Restart Type N (NDB 8.0.13) • ExtraSendBufferMemory This parameter is measured in number of records and is by default set to 256. The maximum size is 992. This parameter specifies the amount of transporter send buffer memory to allocate in addition to any that has been set using  TotalSendBufferMemory ,  SendBufferMemory , or both. Use this parameter to set the scheduling policy and priority of heartbeat threads for management and API nodes. The syntax for setting this parameter is shown here: When setting this parameter, you must specify a policy. This is one of  FIFO  (first in, first in) or  RR  (round robin). This followed optionally by the priority (an integer). HeartbeatThreadPriority =  policy [,  priority ] policy : {FIFO | RR} • MaxScanBatchSize • HeartbeatThreadPriority Version (or later) NDB 8.0.13 Type or units bytes Default 0 Range 0 - 4294967039 (0xFFFFFEFF) Restart Type N (NDB 8.0.13) Version (or later) NDB 8.0.13 Type or units string Default [...] Range ... Restart Type N (NDB 8.0.13) Version (or later) NDB 8.0.13 4155