# Geo\_shape questions & comments **URL:** \ **Category:** Elasticsearch\ **Created:** [January 16, 2013, 1:46pm UTC](https://discuss.elastic.co/t/geo-shape-questions-comments/10373 "2013-01-16T13:46:43Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![gjdev](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/gjdev/32/2528_2.png) [@gjdev](https://discuss.elastic.co/u/gjdev)\ **Post date:** [January 16, 2013, 1:46pm UTC](https://discuss.elastic.co/t/geo-shape-questions-comments/10373/1 "2013-01-16T13:46:43Z")
Many thanks for the implementation of the geo\_shape type and filters! I expect them to be incredibly useful for us. I do have some questions, and some suggestions, that I hope somebody that understands the implementation could answer: - (Suggestion) From reading the documentation I expected that the filters/queries would use the prefixtree indexes to speed things up, but further filter with geometry calculations on the original geometries to decide whether there is an actual "intersection"/"within" relation. The documentation should probably make it more clear that the only filtering that's done is on the hashes, never on the original geometries, and that the depth therefore not only influences the performance, but also the outcome of queries/filters - (Question) A bit more documentation about how the combination of distance\_error\_pct and tree\_levels affects the precision/results of filters would really be appreciated. From the docs and code I'm having a hard time understanding the consequences of altering both values on filters and indexes. - (Suggestion) The algorithm for the "within" (In TermQueryPrefixStrategy) could be improved (imho) by removing hashes from the must-not clause (i.e. hashes for the buffer around the original geometry), when these hashes are already in the "should" clause (i.e. the intersects part of that query). That would provide more consistent behaviour when the filter-geometry and the target-geometry are equal. With the current algorithm, equal geometries will in most cases (but not always) not be found, because the must-not clause will likely contain hashes for points inside the original geometry (i.e. overlapping with hashes in the intersects query). With my suggestion, the "within" query/filter will match any geometry that is equal to or contained within the filter-geometry. - (Question) quote: "Because of current limitations of the algorithm, very large indexed shapes are not deemed to intersect with very small filter shapes". Are there any plans to fix this? (I would expect that when not only the hashes of a geometry, but also the maximum depth is indexed, it would be possible to fix the filters for that. E.g. the intersects filter could then be extended by also filtering with each parent-hash boolean-and with the lavel of that parent-hash. That would find the larger geometries that intersect, without also getting smaller ones outside the filter geo, but intersecting with the parent). - (Question/Suggestion): Are there plans to support "Pre-Indexed-Shapes" also in documents, i.e. specify a pre-indexed shape to be indexed with a new document, instead of adding the geometry itself to that document? I would expect that in many use-cases many of the same geometries will be indexed with multiple docs. Just like with filters/queries the performance could benefit quite a lot if the indexer could just copy the hashes over from an already indexed geometry. - (Question/Suggestion): Imho allowing a serialisation of a geometry as e.g. WKT would not only trim-down on the size of documents, but also on the work that elasticsearch needs to do for serializing/deserializing geometries. Polygons quickly become really big when expressed in JSON... Is this something that is considered and/or that will be accepted when provided in a decent pull-request? Thanks... -- ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 2:56am UTC](https://discuss.elastic.co/t/geo-shape-questions-comments/10373/2 "2017-07-06T02:56:08Z")