Add 'last_cache' and 'distinct_cache' SQL functions (#5828)

* add last_value and distinct_value sql functions

* fixed cache function names

Author: sanderson

content/influxdb3/core/reference/sql/functions/cache.md

@@ -0,0 +1,17 @@
+---
+title: SQL cache functions
+list_title: Cache functions
+description: >
+  Retrieve cached data from {{< product-name >}} caches.
+menu:
+  influxdb3_core:
+    name: Cache
+    parent: sql-functions
+weight: 311
+
+source: /shared/sql-reference/functions/cache.md
+---
+
+<!--
+The content for this page is at /content/shared/sql-reference/functions/cache.md
+-->

content/influxdb3/enterprise/reference/sql/functions/cache.md

@@ -0,0 +1,17 @@
+---
+title: SQL cache functions
+list_title: Cache functions
+description: >
+  Retrieve cached data from {{< product-name >}} caches.
+menu:
+  influxdb3_enterprise:
+    name: Cache
+    parent: sql-functions
+weight: 311
+
+source: /shared/sql-reference/functions/cache.md
+---
+
+<!--
+The content for this page is at /content/shared/sql-reference/functions/cache.md
+-->

content/shared/influxdb3-sample-data/sample-data.md

@@ -25,7 +25,7 @@ to
 
 ##### Schema
 
-- home <em style="opacity: .5">(measurement)</em>
+- home <em style="opacity: .5">(table)</em>
   - **tags**:
     - room
       - Kitchen
@@ -208,7 +208,7 @@ to
 
 ##### Schema
 
-- home_actions <em style="opacity: .5">(measurement)</em>
+- home_actions <em style="opacity: .5">(table)</em>
   - **tags**:
     - room
       - Kitchen
@@ -336,7 +336,7 @@ series use cases that involve seasonality.
 
 ##### Schema
 
-- weather <em style="opacity: .5">(measurement)</em>
+- weather <em style="opacity: .5">(table)</em>
   - **tags**:
     - location
       - Concord
@@ -430,7 +430,7 @@ The Bitcoin price sample dataset provides Bitcoin prices from
 
 ##### Schema
 
-- bitcoin <em style="opacity: .5">(measurement)</em>
+- bitcoin <em style="opacity: .5">(table)</em>
   - **tags**:
     - code
       - EUR
@@ -518,7 +518,7 @@ transformation functions.
 
 ##### Schema
 
-- numbers <em style="opacity: .5">(measurement)</em>
+- numbers <em style="opacity: .5">(table)</em>
   - **fields**
     - a <em style="opacity: .5">(float between -1 and 1)</em>
     - b <em style="opacity: .5">(float between -3 and 3)</em>

content/shared/sql-reference/functions/cache.md

@@ -0,0 +1,56 @@
+
+The {{< product-name >}} SQL implementation supports the following functions
+that return data from {{< product-name >}} caches.
+
+- [distinct_cache](#distinct_cache)
+- [last_cache](#last_cache)
+
+## distinct_cache
+
+Returns data from an {{< product-name >}} distinct value cache.
+
+```sql
+distinct_cache(table_name, cache_name)
+```
+
+#### Arguments
+
+- **table_name**: Name of the table associated with the distinct value cache
+  _(formatted as a string literal)_.
+- **datatype**: Name of the the distinct value cache to query 
+  _(formatted as a string literal)_.
+
+{{< expand-wrapper >}}
+{{% expand "View `distinct_cache` query example" %}}
+
+```sql
+SELECT * FROM distinct_cache('example_table', 'exampleCacheName')
+```
+
+{{% /expand %}}
+{{< /expand-wrapper >}}
+
+## last_cache
+
+Returns data from an {{< product-name >}} last value cache.
+
+```sql
+last_cache(table_name, cache_name)
+```
+
+#### Arguments
+
+- **table_name**: Name of the table associated with the last value cache
+  _(formatted as a string literal)_.
+- **datatype**: Name of the the last value cache to query 
+  _(formatted as a string literal)_.
+
+{{< expand-wrapper >}}
+{{% expand "View `last_cache` query example" %}}
+
+```sql
+SELECT * FROM last_cache('example_table', 'exampleCacheName')
+```
+
+{{% /expand %}}
+{{< /expand-wrapper >}}