Got it .
Thanks,
Weidong
I'm not really sure how well that would work in practice, but you're
welcome to give it a try and see how it goes. You'd get better
column compression but you'd have to return all the geometry type
columns for every query.
Thanks,
Emilio
On 4/2/19 10:53 AM, Weidong Duan wrote:
I’m sorry , to implement the ‘GeometryCollection’
with four-dimension lists of doubles . And the pre email is the
implement of `Geometry`
I know the `MultiPolygon` is implemented
by lists of lists of lists of double values, To
implement the `GeometryCollection`, I use one column
to store the types of
Point,LineString,Polygon,MultiPoint,MultiLineString,MultiPolygon,and
with the another six tuple to store the real data.
e.g.
Type, point_x,point_y,
linestring_x,linestring_y,polygon_x,polygon_y,multipoint_x,multipoint_y,multiLinestring_x,multilinestirng_y,multipolygon_x,multipolygon_y
Is this OK? With the extra columns to make
the ` ORC is a structured data format`
Thanks for your reply,
Weidong
Hello,
The main reason is that ORC is a structured data
format. We can model points as two double
columns (one for x, one for y), line strings as
two lists of double values, polygons as lists of
lists of double values, etc. However, geometry
and geometry collection can contain arbitrary
geometry classes, so they don't have a
consistent model. We could do something like
store the geometry as a single column of WKT
text or WKB bytes, but then you would lose a lot
of the benefits of using a structured file
format in the first place (efficient columnar
compression, dictionary encoding, push down
predicates, etc). However, if you wanted to
implement them anyway, you would need to add
appropriate readers and writers here: https://github.com/locationtech/geomesa/tree/master/geomesa-fs/geomesa-fs-storage/geomesa-fs-storage-orc/src/main/scala/org/locationtech/geomesa/fs/storage/orc/utils
Thanks,
Emilio
On 4/2/19 9:54 AM,
Weidong Duan wrote:
Dear All ,
Geomesa-FS-ORC
does not support `GeometryCollection`
and `Geometry` types. Could you analyze
the consideration about the two types
not supported ? And If I want to add the
two types , Do you have some suggestions
?
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