Issue 10805: DataReader semantics for historical data are insufficient (data-distribution-rtf)
Source:  (, )
Nature: Uncategorized Issue
Severity: 
Summary: Problem:
The current specification provides no solution for the following two use-cases:
·	A Volatile DataReader can receive data from a Transient or persistent DataWriter so it may also be interested in historical data. However a DataReader cannot receive historical data. Just making the DataReader Transient does not solve the problem because the DataReader may also be interested in volatile data.
·	A Transient or Persistent DataReader may not be interested in historical data, there is no way to avoid receiving historical data. A DataReader may be e.g. Transient to avoid receiving data from volatile DataWriters, in addition there may be no interest in historical data.
	
Solution:
Separate the control of receiving historical data from the DataReaders durability interest. The DataReaders Durability interest will specify from which DataWriter it will accept data. A separate call will control (ask for) the retrieval of historical data.
Add the following method
ReturnCode_t get_historical_data(Duration_t max_wait) 
And Transient and Persistent DataReaders should not automatically receive historical data. A consequence is that this invalidates the method
ReturnCode_t wait_for_historical_data(Duration_t max_wait).

Resolution: 
Revised Text: 
Actions taken:
March 5, 2007: received issue
Discussion: 

End of Annotations:=====
ssue ID	PT-DCPS-ARCH-0001
OMG issue ID	
Issue name	DataReader semantics for historical data are insufficient 
Status	PENDING SUBMISSION

Problem:
The current specification provides no solution for the following two use-cases:
·	A Volatile DataReader can receive data from a Transient or persistent DataWriter so it may also be interested in historical data. However a DataReader cannot receive historical data. Just making the DataReader Transient does not solve the problem because the DataReader may also be interested in volatile data.
·	A Transient or Persistent DataReader may not be interested in historical data, there is no way to avoid receiving historical data. A DataReader may be e.g. Transient to avoid receiving data from volatile DataWriters, in addition there may be no interest in historical data.
	
Solution:
Separate the control of receiving historical data from the DataReaders durability interest. The DataReaders Durability interest will specify from which DataWriter it will accept data. A separate call will control (ask for) the retrieval of historical data.
Add the following method
ReturnCode_t get_historical_data(Duration_t max_wait) 
And Transient and Persistent DataReaders should not automatically receive historical data. A consequence is that this invalidates the method
ReturnCode_t wait_for_historical_data(Duration_t max_wait).
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