ESQL: Update docs for new types (#137726)

* Update docs for new types

aggregate_metric_double and dense_vector

* Fix typos

* Try to fix applies_to markers

* Fixes

* Mark conversion functions as preview

* Use consistent links

* Mention TO_DENSE_VECTOR

* Refactor 9.2.0 type limitations and fix cross-repo links

Grouped dense_vector and aggregate_metric_double limitations under single bullet with sub-bullets
Added subheading "Partial support in 9.2.0"
Fixed broken elasticsearch:// cross-repo links to /reference/ format
Converted multi-index paragraph to bullet point
Wrapped explanation in note block with bulleted examples

---------

Co-authored-by: Liam Thompson <[email protected]>

Author: alex-spies

docs/reference/query-languages/esql/_snippets/lists/type-conversion-functions.md

@@ -1,10 +1,12 @@
+* [`TO_AGGREGATE_METRIC_DOUBLE`](../../functions-operators/type-conversion-functions.md#esql-to_aggregate_metric_double) {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview`
 * [`TO_BOOLEAN`](../../functions-operators/type-conversion-functions.md#esql-to_boolean)
 * [`TO_CARTESIANPOINT`](../../functions-operators/type-conversion-functions.md#esql-to_cartesianpoint)
 * [`TO_CARTESIANSHAPE`](../../functions-operators/type-conversion-functions.md#esql-to_cartesianshape)
 * [`TO_DATEPERIOD`](../../functions-operators/type-conversion-functions.md#esql-to_dateperiod)
 * [`TO_DATETIME`](../../functions-operators/type-conversion-functions.md#esql-to_datetime)
 * [`TO_DATE_NANOS`](../../functions-operators/type-conversion-functions.md#esql-to_date_nanos)
 * [`TO_DEGREES`](../../functions-operators/type-conversion-functions.md#esql-to_degrees)
+* [`TO_DENSE_VECTOR`](../../functions-operators/type-conversion-functions.md#esql-to_dense_vector) {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview`
 * [`TO_DOUBLE`](../../functions-operators/type-conversion-functions.md#esql-to_double)
 * [`TO_GEOHASH`](../../functions-operators/type-conversion-functions.md#esql-to_geohash) {applies_to}`stack: preview` {applies_to}`serverless: preview`
 * [`TO_GEOHEX`](../../functions-operators/type-conversion-functions.md#esql-to_geohex) {applies_to}`stack: preview` {applies_to}`serverless: preview`

docs/reference/query-languages/esql/functions-operators/type-conversion-functions.md

@@ -22,6 +22,9 @@ mapped_pages:
 :::
 
 
+:::{include} ../_snippets/functions/layout/to_aggregate_metric_double.md
+:::
+
 :::{include} ../_snippets/functions/layout/to_boolean.md
 :::
 
@@ -43,6 +46,9 @@ mapped_pages:
 :::{include} ../_snippets/functions/layout/to_degrees.md
 :::
 
+:::{include} ../_snippets/functions/layout/to_dense_vector.md
+:::
+
 :::{include} ../_snippets/functions/layout/to_double.md
 :::
 

docs/reference/query-languages/esql/limitations.md

@@ -32,40 +32,41 @@ By default, an {{esql}} query returns up to 1,000 rows. You can increase the num
     * You can use `to_datetime` to cast to millisecond dates to use unsupported functions
 
 * `double` (`float`, `half_float`, `scaled_float` are represented as `double`)
+* `dense_vector` {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview`
 * `ip`
 * `keyword` [family](/reference/elasticsearch/mapping-reference/keyword.md) including `keyword`, `constant_keyword`, and `wildcard`
 * `int` (`short` and `byte` are represented as `int`)
 * `long`
 * `null`
 * `text` [family](/reference/elasticsearch/mapping-reference/text.md) including `text`, `semantic_text` and `match_only_text`
-* {applies_to}`stack: preview` {applies_to}`serverless: preview` `unsigned_long`
+* `unsigned_long` {applies_to}`stack: preview` {applies_to}`serverless: preview`
 * `version`
 * Spatial types
 
     * `geo_point`
     * `geo_shape`
     * `point`
     * `shape`
-* TSDB metrics {preview}`9.2`
-   * `counter` 
-   * `gauge` 
+* TSDB metrics {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview`
+   * `counter`
+   * `gauge`
    * `aggregate_metric_double`
 
 
-
 ### Unsupported types [_unsupported_types]
 
 {{esql}} does not yet support the following field types:
 
 ::::{tab-set}
 :::{tab-item} 9.0-9.1
+* `dense_vector`
 * TSDB metrics
-   * `counter` 
-   * `gauge` 
+   * `counter`
+   * `gauge`
    * `aggregate_metric_double`
 :::
 :::{tab-item} 9.2+
-This limitation no longer exists and TSDB metrics are now supported (preview).
+This limitation no longer exists and TSDB metrics and `dense_vector` are now supported (preview).
 :::
 ::::
 * Date/time
@@ -104,12 +105,19 @@ Some [field types](/reference/elasticsearch/mapping-reference/field-data-types.m
     * `cartesian_shape`
 
 
-In addition, when [querying multiple indexes](/reference/query-languages/esql/esql-multi-index.md), it’s possible for the same field to be mapped to multiple types. These fields cannot be directly used in queries or returned in results, unless they’re [explicitly converted to a single type](/reference/query-languages/esql/esql-multi-index.md#esql-multi-index-union-types).
+- In addition, when [querying multiple indexes](/reference/query-languages/esql/esql-multi-index.md), it’s possible for the same field to be mapped to multiple types. These fields cannot be directly used in queries or returned in results, unless they’re [explicitly converted to a single type](/reference/query-languages/esql/esql-multi-index.md#esql-multi-index-union-types).
 
-* `dense_vector` field type is partially supported. [`KNN` function](elasticsearch://reference/query-languages/esql/functions-operators/dense-vector-functions.md#esql-knn) queries will work and any field data will be retrieved as part of the results. However, the type will appear as `unsupported` when the `KNN` function is not used.
+#### Partial support in 9.2.0
 
-This means that `FROM test` will not retrieve `dense_vector` data. But, `FROM test WHERE KNN("dense_vector_field", [0, 1, 2, ...])` will retrieve data.
+* {applies_to}`stack: preview 9.2.0` The following types are only partially supported on 9.2.0. This is fixed in 9.2.1:
+  * `dense_vector`: The [`KNN` function](/reference/query-languages/esql/functions-operators/dense-vector-functions.md#esql-knn) and the [`TO_DENSE_VECTOR` function](/reference/query-languages/esql/functions-operators/type-conversion-functions.md#esql-to_dense_vector) will work and any field data will be retrieved as part of the results. However, the type will appear as `unsupported` when these functions are not used.
+  * `aggregate_metric_double`: Using the [`TO_AGGREGATE_METRIC_DOUBLE` function](/reference/query-languages/esql/functions-operators/type-conversion-functions.md#esql-to_aggregate_metric_double) will work and any field data will be retrieved as part of the results. However, the type will appear as `unsupported` if this function is not used.
 
+    :::{note}
+    This means that a simple query like `FROM test` will not retrieve `dense_vector` or `aggregate_metric_double` data. However, using the appropriate functions will work:
+    * `FROM test WHERE KNN("dense_vector_field", [0, 1, 2, ...])`
+    * `FROM test | EVAL agm_data = TO_AGGREGATE_METRIC_DOUBLE(aggregate_metric_double_field)`
+    :::
 
 ## _source availability [esql-_source-availability]