!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! SDDL Name:	DATASET_LINK.SDDL
!
! Purpose:      This SDDL file defines the DATASET_LINK relation.
!
! Modification History:
!
!   Date       OPR      Who                       Reason
! --------   -------    ----   ------------------------------------------------
! 01/30/01    44862      Baum   Original implementation
!
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!
!
 
LANGUAGE	SQL

RECORD  DATASET_LINK_TYPE
 
!------------------------------------------------------------------------------
!
!   RECORD INFORMATION
!
!------------------------------------------------------------------------------
 
 
DESCRIPTION       "This relation is used to link the dataset rootname to 
                   programmatic ids with keys to facilitate joins to other
                   relations. "

!------------------------------------------------------------------------------
!
!   FIELD INFORMATION
!
!------------------------------------------------------------------------------

    FIELD  dataset_rootname
        TYPE            C9
        DESCRIPTION     "IPPPSSOOT for jitter or astrometry datasets"

    END_FIELD

    FIELD  dataset_type
        TYPE            C3
        DESCRIPTION     "Either FGS or AST, for FGS obslogs or astrometry,
                         respectively."

    END_FIELD

    FIELD program_id
        TYPE        C3
        UNITS	    "BASE_36"
        DESCRIPTION "When a proposal is accepted into the PMDB by SPSS it must
		    be assigned a unique 3 character base 36 program identifier.
		    This is done by the PMDB/ACCEPT_PROP command.
                    It is used for identification of proposals by spacecraft 
                    and OPUS software. It is also used in the OPUS and DADS 
                    rootname for all archived science data files. 
                    Because of flight design software, program_id must be
                    three characters. "
    END_FIELD

    FIELD obset_id
        TYPE        C2
        UNITS	    "BASE_36"
        DESCRIPTION "An observation set is a collection of one or more 
		    alignments that are grouped together based on FGS pointing 
		    requirements.  That is, if multiple alignments can all be 
		    executed using the same guide star pair, they are grouped
		    into the same observation set. "
    END_FIELD

    FIELD ob_number
        TYPE        C2
        UNITS	    "BASE_36"
        DESCRIPTION "Observations are numbered sequentially throughout
                    an observation set and are assigned by SMS/Gen.
                    An ob_number is _NOT_ the same as an obset_ID. "
    END_FIELD
END_RECORD
 
 
!------------------------------------------------------------------------------
!
!   RELATION DECLARATION
!
!------------------------------------------------------------------------------
 
 
RELATION  dataset_link
 
    TYPE             DATASET_LINK_TYPE
 
    DESCRIPTION      "Links datasets to programmatic IDs"
 
    SUBSYSTEM_USING  "OPUS"

    INDEX  dataset_link_1
        TYPE         unique, clustered
        FIELDS       dataset_rootname, dataset_type, program_id, obset_id, 
                     ob_number
    END_INDEX

    INDEX  dataset_link_2
        TYPE         nonclustered
        FIELDS       program_id, obset_id, ob_number, dataset_type
    END_INDEX

END_RELATION