ES|QL: Add TBUCKET function

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

@@ -1,2 +1,3 @@
 * [`BUCKET`](../../functions-operators/grouping-functions.md#esql-bucket)
+* [`TBUCKET`](../../functions-operators/grouping-functions.md#esql-tbucket)
 * [`CATEGORIZE`](../../functions-operators/grouping-functions.md#esql-categorize)

docs/reference/query-languages/esql/functions-operators/grouping-functions.md

@@ -16,7 +16,10 @@ The [`STATS`](/reference/query-languages/esql/commands/stats-by.md) command supp
 :::{include} ../_snippets/functions/layout/bucket.md
 :::
 
-:::{note} 
+:::{include} ../_snippets/functions/layout/tbucket.md
+:::
+
+:::{note}
 The `CATEGORIZE` function requires a [platinum license](https://www.elastic.co/subscriptions).
 :::
 

x-pack/plugin/esql-core/src/test/resources/mapping-odd-timestamp.json

@@ -0,0 +1,16 @@
+{
+    "properties": {
+        "@timestamp": {
+            "type": "boolean"
+        },
+        "client_ip": {
+            "type": "ip"
+        },
+        "event_duration": {
+            "type": "long"
+        },
+        "message": {
+            "type": "keyword"
+        }
+    }
+}

x-pack/plugin/esql/qa/testFixtures/src/main/resources/k8s-timeseries.csv-spec

@@ -96,6 +96,18 @@ max(rate(network.total_bytes_in)): double | time_bucket:date
 // end::rate-result[]
 ;
 
+oneRateWithTBucket
+required_capability: metrics_command
+required_capability: tbucket
+TS k8s
+| STATS max(rate(network.total_bytes_in)) BY time_bucket = tbucket(5minute)
+| SORT time_bucket DESC | LIMIT 2;
+
+max(rate(network.total_bytes_in)): double | time_bucket:date
+6.980660660660663                         | 2024-05-10T00:20:00.000Z
+23.702205882352942                        | 2024-05-10T00:15:00.000Z
+;
+
 twoRatesWithBucket
 required_capability: metrics_command
 TS k8s | STATS max(rate(network.total_bytes_in)), sum(rate(network.total_bytes_in)) BY time_bucket = bucket(@timestamp,5minute) | SORT time_bucket DESC | LIMIT 3;
@@ -106,6 +118,16 @@ max(rate(network.total_bytes_in)):double | sum(rate(network.total_bytes_in)):dou
 14.97039381153305                        | 63.00652190262822                        | 2024-05-10T00:10:00.000Z
 ;
 
+twoRatesWithTBucket
+required_capability: metrics_command
+required_capability: tbucket
+TS k8s | STATS max(rate(network.total_bytes_in)), sum(rate(network.total_bytes_in)) BY time_bucket = tbucket(5minute) | SORT time_bucket DESC | LIMIT 3;
+
+max(rate(network.total_bytes_in)):double | sum(rate(network.total_bytes_in)):double | time_bucket:datetime    
+6.980660660660663                        | 23.959973363184154                       | 2024-05-10T00:20:00.000Z
+23.702205882352942                       | 94.9517511187984                         | 2024-05-10T00:15:00.000Z
+14.97039381153305                        | 63.00652190262822                        | 2024-05-10T00:10:00.000Z
+;
 
 oneRateWithBucketAndCluster
 required_capability: metrics_command