Changes between Version 12 and Version 13 of FDORfc39


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Timestamp:
06/25/09 12:16:26 (15 years ago)
Author:
danstoica
Comment:

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  • FDORfc39

    v12 v13  
    2929Along with the standard named spatial operators which FDO already suppotrs, OGS specifies the Relate predicate based on the pattern matrix which has the advantage that clients can test for a large number of spatial relationships and fine tune the particular relationship being tested; This pattern matrix is called the Extended Nine-Intersection Model (DE-9IM); see Reference [1].
    3030
    31 This model has been adopted by MS SqlServer 2008 and PostGIS databases following the OGS syntax, like:
     31This model has been adopted by MS SqlServer 2008 and PostGIS databases following the OGS syntax; see References [3], [4]. Example:
    3232      STRelate('T*F**F***') for 'Within'
    3333
    34 Oracle supports Relate as well but in more readable form, like:
     34Oracle also supports Relate and DE-9IM model but in more readable form; see Reference [2]. Example:
    3535      SDO_RELATE(... 'mask=touch+coveredby') = 'TRUE';
    3636
    37 Therefore supporting Relate implies providing the ability to generate DE-9IM strings based on a OR mask . Note it is not possible to generate an unambiguous OR mask given a DE-9IM string.
    3837
    3938== Proposed Solution ==
    4039
    41 Obviously generating valid strings for spatial operation combinations in DE-9IM form is not easy and this task must be accomplished by FDO. In turn, FDO will present the user the list of available named operators which can be combined in a bitmapped mask.
     40Supporting Relate implies providing the ability to generate DE-9IM strings based on a OR mask. Note it is not possible to generate an unambiguous OR mask given a DE-9IM string.
     41
     42Obviously generating valid strings for spatial operation combinations in DE-9IM form is not convenient for the user and this task must be accomplished internally by FDO. In turn, FDO will present the user the list of available named operators which can be combined in a bitmapped mask.
    4243
    4344A number of changes in FDO are proposed:
     
    157158== Test Plan ==
    158159
     160- create a test datastore with various geometry types and various types of interaction. Good examples can be found in [1].
     161- test Relate with invalid mask. Exceptions should be thrown.
     162- test Relate queries with just one spatial operator. The results should match those from queries with named operators (i.e. existing style)
     163- test Relate with different spatial operation combinations. Manually validate the results.
     164
    159165== Funding/Resources ==
    160166