Temporary Storage Queue names are dynamically defined in the application program, while TDQs must first be defined in the DCT (Destination Control Table). When a TDQ contains certain amount of records (Trigger level), A CICS transaction can be started automatically. This does not happen when using a TSQ. TDQ (extra partition) may be used by batch application; TSQ cannot be accessed in batch. The Transient Data Queue is actually a QSAM file. You may update an existing item in a TSQ. A record in a TDQ cannot be updated. Records in TSQ can be read randomly. The TDQ can be read only sequentially. Records inTemporary Storage can be read more than once, while recordes stored in Temporary Data Queues cannot. With TDQs it is "one read" only.