[DOCS] Remove deprecated `geo_shape` parameters (#74519)

* Removes docs and references for the following `geo_shape` mapping parameters:
  * `tree`
  * `tree_levels`
  * `strategy`
  * `distance_error_pct`
* Updates a related breaking change.

Relates to #70850

docs/reference/ingest/processors/enrich.asciidoc

@@ -20,7 +20,7 @@ See <<ingest-enriching-data,enrich data>> section for more information about how
 | `ignore_missing`   | no        | false                | If `true` and `field` does not exist, the processor quietly exits without modifying the document
 | `override`         | no        | true                 | If processor will update fields with pre-existing non-null-valued field. When set to `false`, such fields will not be touched.
 | `max_matches`      | no        | 1                    | The maximum number of matched documents to include under the configured target field. The `target_field` will be turned into a json array if `max_matches` is higher than 1, otherwise `target_field` will become a json object. In order to avoid documents getting too large, the maximum allowed value is 128.
-| `shape_relation`   | no        | `INTERSECTS`         | A spatial relation operator used to match the <<geo-shape,geo_shape>> of incoming documents to documents in the enrich index. This option is only used for `geo_match` enrich policy types. The <<spatial-strategy, geo_shape strategy>> mapping parameter determines which spatial relation operators are available. See <<_spatial_relations>> for operators and more information.
+| `shape_relation`   | no        | `INTERSECTS`         | A spatial relation operator used to match the <<geo-shape,geo_shape>> of incoming documents to documents in the enrich index. This option is only used for `geo_match` enrich policy types. See <<_spatial_relations>> for operators and more information.
 
 include::common-options.asciidoc[]
 |======

docs/reference/mapping/types/geo-shape.asciidoc

@@ -24,61 +24,6 @@ type.
 |=======================================================================
 |Option |Description| Default
 
-|`tree` |deprecated[6.6, PrefixTrees no longer used] Name of the PrefixTree
-implementation to be used: `geohash` for GeohashPrefixTree and `quadtree`
-for QuadPrefixTree. Note: This parameter is only relevant for `term` and
-`recursive` strategies.
-| `quadtree`
-
-|`precision` |deprecated[6.6, PrefixTrees no longer used] This parameter may
-be used instead of `tree_levels` to set an appropriate value for the
-`tree_levels` parameter. The value specifies the desired precision and
-Elasticsearch will calculate the best tree_levels value to honor this
-precision. The value should be a number followed by an optional distance
-unit. Valid distance units include: `in`, `inch`, `yd`, `yard`, `mi`,
-`miles`, `km`, `kilometers`, `m`,`meters`, `cm`,`centimeters`, `mm`,
-`millimeters`. Note: This parameter is only relevant for `term` and
-`recursive` strategies.
-| `50m`
-
-|`tree_levels` |deprecated[6.6, PrefixTrees no longer used] Maximum number
-of layers to be used by the PrefixTree. This can be used to control the
-precision of shape representations andtherefore how many terms are
-indexed. Defaults to the default value of the chosen PrefixTree
-implementation. Since this parameter requires a certain level of
-understanding of the underlying implementation, users may use the
-`precision` parameter instead. However, Elasticsearch only uses the
-tree_levels parameter internally and this is what is returned via the
-mapping API even if you use the precision parameter. Note: This parameter
-is only relevant for `term` and `recursive` strategies.
-| various
-
-|`strategy` |deprecated[6.6, PrefixTrees no longer used] The strategy
-parameter defines the approach for how to represent shapes at indexing
-and search time. It also influences the capabilities available so it
-is recommended to let Elasticsearch set this parameter automatically.
-There are two strategies available: `recursive`, and `term`.
-Recursive and Term strategies are deprecated and will be removed in a
-future version. While they are still available, the Term strategy
-supports point types only (the `points_only` parameter will be
-automatically set to true) while Recursive strategy supports all
-shape types. (IMPORTANT: see <<prefix-trees, Prefix trees>> for more
-detailed information about these strategies)
-| `recursive`
-
-|`distance_error_pct` |deprecated[6.6, PrefixTrees no longer used] Used as a
-hint to the PrefixTree about how precise it should be. Defaults to 0.025 (2.5%)
-with 0.5 as the maximum supported value. PERFORMANCE NOTE: This value will
-default to 0 if a `precision` or `tree_level` definition is explicitly defined.
-This guarantees spatial precision at the level defined in the mapping. This can
-lead to significant memory usage for high resolution shapes with low error
-(e.g., large shapes at 1m with < 0.001 error). To improve indexing performance
-(at the cost of query accuracy) explicitly define `tree_level` or `precision`
-along with a reasonable `distance_error_pct`, noting that large shapes will have
-greater false positives. Note: This parameter is only relevant for `term` and
-`recursive` strategies.
-| `0.025`
-
 |`orientation`
 a|Optional. Vertex order for the shape's coordinates list.
 
@@ -106,15 +51,6 @@ ring (hole) vertices in clockwise order.
 Individual GeoJSON or WKT documents can override this parameter.
 | `RIGHT`
 
-|`points_only` |deprecated[6.6, PrefixTrees no longer used] Setting this option to
-`true` (defaults to `false`) configures the `geo_shape` field type for point
-shapes only (NOTE: Multi-Points are not yet supported). This optimizes index and
-search performance for the `geohash` and `quadtree` when it is known that only points
-will be indexed. At present geo_shape queries can not be executed on `geo_point`
-field types. This option bridges the gap by improving point performance on a
-`geo_shape` field so that `geo_shape` queries are optimal on a point only field.
-| `false`
-
 |`ignore_malformed` |If true, malformed GeoJSON or WKT shapes are ignored. If
 false (default), malformed GeoJSON and WKT shapes throw an exception and reject the
 entire document.
@@ -139,86 +75,8 @@ GeoShape types are indexed by decomposing the shape into a triangular mesh and
 indexing each triangle as a 7 dimension point in a BKD tree. This provides
 near perfect spatial resolution (down to 1e-7 decimal degree precision) since all
 spatial relations are computed using an encoded vector representation of the
-original shape instead of a raster-grid representation as used by the
-<<prefix-trees>> indexing approach. Performance of the tessellator primarily
-depends on the number of vertices that define the polygon/multi-polygon. While
-this is the default indexing technique prefix trees can still be used by setting
-the `tree` or `strategy` parameters according to the appropriate
-<<geo-shape-mapping-options>>. Note that these parameters are now deprecated
-and will be removed in a future version.
-
-*IMPORTANT NOTES*
-
-`CONTAINS` relation query - when using the new default vector indexing strategy, `geo_shape`
-queries with `relation` defined as `contains` are supported for indices created with
-ElasticSearch 7.5.0 or higher.
-
-
-[[prefix-trees]]
-[discrete]
-==== Prefix trees
-
-deprecated[6.6, PrefixTrees no longer used] To efficiently represent shapes in
-an inverted index, Shapes are converted into a series of hashes representing
-grid squares (commonly referred to as "rasters") using implementations of a
-PrefixTree. The tree notion comes from the fact that the PrefixTree uses multiple
-grid layers, each with an increasing level of precision to represent the Earth.
-This can be thought of as increasing the level of detail of a map or image at higher
-zoom levels. Since this approach causes precision issues with indexed shape, it has
-been deprecated in favor of a vector indexing approach that indexes the shapes as a
-triangular mesh (see <<geoshape-indexing-approach>>).
-
-Multiple PrefixTree implementations are provided:
-
-* GeohashPrefixTree - Uses
-{wikipedia}/Geohash[geohashes] for grid squares.
-Geohashes are base32 encoded strings of the bits of the latitude and
-longitude interleaved. So the longer the hash, the more precise it is.
-Each character added to the geohash represents another tree level and
-adds 5 bits of precision to the geohash. A geohash represents a
-rectangular area and has 32 sub rectangles. The maximum number of levels
-in Elasticsearch is 24; the default is 9.
-* QuadPrefixTree - Uses a
-{wikipedia}/Quadtree[quadtree] for grid squares.
-Similar to geohash, quad trees interleave the bits of the latitude and
-longitude the resulting hash is a bit set. A tree level in a quad tree
-represents 2 bits in this bit set, one for each coordinate. The maximum
-number of levels for the quad trees in Elasticsearch is 29; the default is 21.
-
-[[spatial-strategy]]
-[discrete]
-===== Spatial strategies
-deprecated[6.6, PrefixTrees no longer used]  The indexing implementation
-selected relies on a SpatialStrategy for choosing how to decompose the shapes
-(either as grid squares or a tessellated triangular mesh). Each strategy
-answers the following:
-
-* What type of Shapes can be indexed?
-* What types of Query Operations and Shapes can be used?
-* Does it support more than one Shape per field?
-
-The following Strategy implementations (with corresponding capabilities)
-are provided:
-
-[cols="<,<,<,<",options="header",]
-|=======================================================================
-|Strategy |Supported Shapes |Supported Queries |Multiple Shapes
-
-|`recursive`  |<<input-structure, All>> |`INTERSECTS`, `DISJOINT`, `WITHIN`, `CONTAINS` |Yes
-|`term` |<<geo-point-type, Points>> |`INTERSECTS` |Yes
-
-|=======================================================================
-
-[discrete]
-===== Accuracy
-
-`Recursive` and `Term` strategies do not provide 100% accuracy and depending on
-how they are configured it may return some false positives for `INTERSECTS`,
-`WITHIN` and `CONTAINS` queries, and some false negatives for `DISJOINT` queries.
-To mitigate this, it is important to select an appropriate value for the tree_levels
-parameter and to adjust expectations accordingly. For example, a point may be near
-the border of a particular grid cell and may thus not match a query that only matches
-the cell right next to it -- even though the shape is very close to the point.
+original shape. Performance of the tessellator primarily
+depends on the number of vertices that define the polygon/multi-polygon.
 
 [discrete]
 ===== Example
@@ -238,33 +96,6 @@ PUT /example
 --------------------------------------------------
 // TESTSETUP
 
-This mapping definition maps the location field to the geo_shape
-type using the default vector implementation. It provides
-approximately 1e-7 decimal degree precision.
-
-[discrete]
-===== Performance considerations with Prefix Trees
-
-deprecated[6.6, PrefixTrees no longer used] With prefix trees,
-Elasticsearch uses the paths in the tree as terms in the inverted index
-and in queries. The higher the level (and thus the precision), the more
-terms are generated. Of course, calculating the terms, keeping them in
-memory, and storing them on disk all have a price. Especially with higher
-tree levels, indices can become extremely large even with a modest amount
-of data. Additionally, the size of the features also matters. Big, complex
-polygons can take up a lot of space at higher tree levels. Which setting
-is right depends on the use case. Generally one trades off accuracy against
-index size and query performance.
-
-The defaults in Elasticsearch for both implementations are a compromise
-between index size and a reasonable level of precision of 50m at the
-equator. This allows for indexing tens of millions of shapes without
-overly bloating the resulting index too much relative to the input size.
-
-[NOTE]
-Geo-shape queries on geo-shapes implemented with PrefixTrees will not be executed if
-<<query-dsl-allow-expensive-queries, `search.allow_expensive_queries`>> is set to false.
-
 [[input-structure]]
 [discrete]
 ==== Input Structure
@@ -292,8 +123,6 @@ points.
 and a LineString).
 |`N/A` |`BBOX` |`envelope` |A bounding rectangle, or envelope, specified by
 specifying only the top left and bottom right points.
-|`N/A` |`N/A` |`circle` |A circle specified by a center point and radius with
-units, which default to `METERS`.
 |=======================================================================
 
 [NOTE]
@@ -641,16 +470,10 @@ POST /example/_doc
 [discrete]
 ===== Circle
 
-Elasticsearch supports a `circle` type, which consists of a center
-point with a radius.
-
-IMPORTANT: You cannot index the `circle` type using the default
-<<geoshape-indexing-approach,BKD tree indexing approach>>. Instead, use a
+Neither GeoJSON nor WKT supports a point-radius circle type. Instead, use a
 <<ingest-circle-processor,circle ingest processor>> to approximate the circle as
 a <<geo-polygon,`polygon`>>.
 
-*NOTE:* Neither GeoJSON or WKT support a point-radius circle type.
-
 [discrete]
 ==== Sorting and Retrieving index Shapes
 

docs/reference/migration/migrate_8_0/mappings.asciidoc

@@ -94,22 +94,23 @@ mappings with java-time formats.
 For a detailed migration guide, see the {ref}/migrate-to-java-time.html[Java
 time migration guide].
 ====
-// end::notable-breaking-changes[]
 
 [[geo-shape-strategy]]
-.The `strategy` parameter on `geo_shape` mappings now rejects unknown strategies.
+.Several `geo_shape` mapping parameters have been removed.
 [%collapsible]
 ====
 *Details* +
-The only permissible values for the `strategy` parameter on `geo_shape` mappings
-are `term` and `recursive`. In 7.x if a non-permissible value was used as a
-parameter here, the mapping would silently fall back to using `recursive`. The
-mapping will now be rejected instead.
+The following `geo_shape` mapping parameters were deprecated in 6.6:
+
+* `tree`
+* `tree_levels`
+* `strategy`
+* `distance_error_pct`
+
+These parameters have been removed in 8.0.0.
 
 *Impact* +
-This will have no impact on existing mappings created with non-permissible
-strategy values, as they will already be serializing themselves as if they
-had been configured as `recursive`. New indexes will need to use one of the
-permissible strategies, or preferably not define a strategy at all and use
-the far more efficient BKD index.
+In 8.0, you can no longer create mappings that include these parameters.
+However, 7.x indices that use these mapping parameters will continue to work.
 ====
+// end::notable-breaking-changes[]

docs/reference/query-dsl.asciidoc

@@ -49,8 +49,6 @@ the stability of the cluster. Those queries can be categorised as follows:
 
 * <<joining-queries,Joining queries>>
 
-* Queries on <<prefix-trees,deprecated geo-shapes>>
-
 * Queries that may have a high per-document cost:
 ** <<query-dsl-script-score-query,`script_score` queries>>
 ** <<query-dsl-percolate-query,`percolate` queries>>

docs/reference/query-dsl/geo-shape-query.asciidoc

@@ -230,9 +230,6 @@ GET /example/_search
 
 ==== Spatial Relations
 
-The <<spatial-strategy, geo_shape strategy>> mapping parameter determines which
-spatial relation operators may be used at search time.
-
 The following is a complete list of spatial relation operators available when
 searching a geo field:
 
@@ -257,12 +254,6 @@ is not mapped.
 [[geo-shape-query-notes]]
 ==== Notes
 
-* Geo-shape queries on geo-shapes implemented with
-  <<prefix-trees, `PrefixTrees`>> will not be executed if
-  <<query-dsl-allow-expensive-queries, `search.allow_expensive_queries`>> is set
-  to false.
-
-
 * When data is indexed in a `geo_shape` field as an array of shapes, the arrays
   are treated as one shape. For this reason, the following requests are
   equivalent.