• Defaut values:
NULL/void: will never return an answer to a query using this parameter (TBC, seems ADQL-related. To be corrected if it is a limitation of the client)
For float / double : -inf for *_min +inf for *_max – still TBC (NaN won't do). To be tested on a real case.
Not needed for strings? (i.e. NULL/void is OK?)
Default behavior looks OK in fact. If we need to preserve the NULL values on queried parameters (ie, when NULL is considered as "I don't know"), can be done with a OR … param = NULL (on option in the client? This is feasible manually with TapHandle)
• UCDs: to be reviewed against PDS4 and IPDA, and completed
access_format = "PDS3label" (it has to be here: we need to know that there is a detached label)
then access_url points to the label, and data_access_url points to the file (param is mandatory in this case - although the data file name is in the label, it can be in another directory)
A script can then recover both files and do something with them. This mechanism can be extended to other formats with detached labels (ENVI…).
- Check Check solution with datalink first