Context Concepts

i. Handling large amounts of data

• Work together
  

• Work in a consistent way

• Experiment with programs and new code
  

• Know what data and code was used
  

• Keep data private

• Make data public

• Throw away data

  
  

Everything within the Astro-Wise Environment

Current situation

• Persistent attributes identify data
  
  Attributes can be queried to select data
  

• Users can create and update
  

  Users can not delete
  

Future

• Use Context to enforce standard behaviour
  
  Use (Python) queries for flexibility
  

ii. Context attributes

• Instrument

• Project - The project or survey to which data belong.

• Derivation and Workflow

  • People responsible for a project.

  • Methods (TBC)

  • Qualification

• User - The user that created the data

• Privileges

Definitions

• Project defines users and responsible users

• Project responsible sets default privileges
  For each persistent class
  

• Project privileges overrule user priviliges
  

• Defaults apply to new data
  

• Privileges can be changed:
  From user->project, project->public
  
  

• Only non-public data can be deleted
  

• Tool is needed to change priviliges
  To follow references
  

• Tool is needed to delete data
  If not referenced
  

iii. Examples

context.set(instrument='OCAM')

context.set(project='PET')

context.set_default_privilege(project='PET', BiasFrame, 'public')

context.set_default_privilege(project='PET', ScienceFrame, 'project')

EXECUTE AWOPER.AWSECURITY.SET_INSTRUMENT('WFI');

iv. Implementation

• Use Virtual Private Database functionality
  

• Each new object has (hidden) attributes in the database
  

• Central tables specifying
  

  • projects

  • users

  • default priviliges

  • more
    

    
    

• Policy functions that are always executed