ESQL: Rename command from INLINESTATS to INLINE STATS (#134827)

This simply renames `INLINESTATS` to `INLINE STATS`.

The `INLINESTATS` is still kept working for now, but it emits a
deprecation warning.

Closes #133998

Author: bpintea

docs/reference/query-languages/esql/_snippets/commands/examples/inlinestats.csv-spec/avg-salaries-where.md

@@ -3,9 +3,9 @@
 ```esql
 FROM employees
 | KEEP emp_no, salary
-| INLINESTATS avg_lt_50 = ROUND(AVG(salary)) WHERE salary < 50000,
-              avg_lt_60 = ROUND(AVG(salary)) WHERE salary >=50000 AND salary < 60000,
-              avg_gt_60 = ROUND(AVG(salary)) WHERE salary >= 60000
+| INLINE STATS avg_lt_50 = ROUND(AVG(salary)) WHERE salary < 50000,
+               avg_lt_60 = ROUND(AVG(salary)) WHERE salary >=50000 AND salary < 60000,
+               avg_gt_60 = ROUND(AVG(salary)) WHERE salary >= 60000
 ```
 
 | emp_no:integer | salary:integer | avg_lt_50:double | avg_lt_60:double | avg_gt_60:double |

docs/reference/query-languages/esql/_snippets/commands/examples/inlinestats.csv-spec/max-salary-without-by.md

@@ -3,7 +3,7 @@
 ```esql
 FROM employees
 | KEEP emp_no, languages, salary
-| INLINESTATS max_salary = MAX(salary)
+| INLINE STATS max_salary = MAX(salary)
 ```
 
 | emp_no:integer | languages:integer | salary:integer | max_salary:integer |

docs/reference/query-languages/esql/_snippets/commands/examples/inlinestats.csv-spec/max-salary.md

@@ -3,7 +3,7 @@
 ```esql
 FROM employees
 | KEEP emp_no, languages, salary
-| INLINESTATS max_salary = MAX(salary) BY languages
+| INLINE STATS max_salary = MAX(salary) BY languages
 ```
 
 | emp_no:integer | salary:integer | max_salary:integer | languages:integer |

docs/reference/query-languages/esql/_snippets/commands/examples/inlinestats.csv-spec/multi-agg-multi-grouping.md

@@ -6,7 +6,7 @@ FROM employees
 | KEEP emp_no, languages, salary, hire_date
 | EVAL tenure = DATE_DIFF("year", hire_date, now())
 | DROP hire_date
-| INLINESTATS avg_salary = AVG(salary), count = count(*) BY languages, tenure
+| INLINE STATS avg_salary = AVG(salary), count = count(*) BY languages, tenure
 ```
 
 | emp_no:integer | salary:integer | avg_salary:double | count:long | languages:integer | tenure:integer |

docs/reference/query-languages/esql/kibana/definition/commands/inline_stats.json

@@ -51,9 +51,8 @@
 import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.ENABLE_FORK_FOR_REMOTE_INDICES;
 import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.ENABLE_LOOKUP_JOIN_ON_REMOTE;
 import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.FORK_V9;
-import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.INLINESTATS;
-import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.INLINESTATS_SUPPORTS_REMOTE;
-import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.INLINESTATS_V11;
+import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.INLINE_STATS;
+import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.INLINE_STATS_SUPPORTS_REMOTE;
 import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.JOIN_LOOKUP_V12;
 import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.JOIN_PLANNING_V1;
 import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.METADATA_FIELDS_REMOTE_TEST;
@@ -140,16 +139,15 @@ protected void shouldSkipTest(String testName) throws IOException {
         assumeFalse("can't test with _index metadata", (remoteMetadata == false) && hasIndexMetadata(testCase.query));
         Version oldVersion = Version.min(Clusters.localClusterVersion(), Clusters.remoteClusterVersion());
         assumeTrue("Test " + testName + " is skipped on " + oldVersion, isEnabled(testName, instructions, oldVersion));
-        if (testCase.requiredCapabilities.contains(INLINESTATS.capabilityName())
-            || testCase.requiredCapabilities.contains(INLINESTATS_V11.capabilityName())
+        if (testCase.requiredCapabilities.contains(INLINE_STATS.capabilityName())
             || testCase.requiredCapabilities.contains(JOIN_PLANNING_V1.capabilityName())) {
             assumeTrue(
-                "INLINESTATS in CCS not supported for this version",
-                hasCapabilities(adminClient(), List.of(INLINESTATS_SUPPORTS_REMOTE.capabilityName()))
+                "INLINE STATS in CCS not supported for this version",
+                hasCapabilities(adminClient(), List.of(INLINE_STATS_SUPPORTS_REMOTE.capabilityName()))
             );
             assumeTrue(
-                "INLINESTATS in CCS not supported for this version",
-                hasCapabilities(remoteClusterClient(), List.of(INLINESTATS_SUPPORTS_REMOTE.capabilityName()))
+                "INLINE STATS in CCS not supported for this version",
+                hasCapabilities(remoteClusterClient(), List.of(INLINE_STATS_SUPPORTS_REMOTE.capabilityName()))
             );
         }
         if (testCase.requiredCapabilities.contains(JOIN_LOOKUP_V12.capabilityName())) {

x-pack/plugin/esql/qa/server/multi-clusters/src/javaRestTest/java/org/elasticsearch/xpack/esql/ccq/MultiClusterSpecIT.java

@@ -466,10 +466,10 @@ public void assertDriverData(Map<String, Object> driverMetadata, Map<String, Obj
 
     @AwaitsFix(bugUrl = "disabled until JOIN infrastructrure properly lands")
     public void testInlineStatsProfile() throws IOException {
-        assumeTrue("INLINESTATS only available on snapshots", Build.current().isSnapshot());
+        assumeTrue("INLINE STATS only available on snapshots", Build.current().isSnapshot());
         indexTimestampData(1);
 
-        RequestObjectBuilder builder = requestObjectBuilder().query(fromIndex() + " | INLINESTATS AVG(value) | SORT value ASC");
+        RequestObjectBuilder builder = requestObjectBuilder().query(fromIndex() + " | INLINE STATS AVG(value) | SORT value ASC");
         builder.profile(true);
         if (Build.current().isSnapshot()) {
             // Lock to shard level partitioning, so we get consistent profile output

x-pack/plugin/esql/qa/server/single-node/src/javaRestTest/java/org/elasticsearch/xpack/esql/qa/single_node/RestEsqlIT.java

@@ -1212,7 +1212,7 @@ public void testComplexFieldNames() throws IOException {
     }
 
     /**
-     * INLINESTATS <strong>can</strong> group on {@code NOW()}. It's a little silly, but
+     * INLINE STATS <strong>can</strong> group on {@code NOW()}. It's a little silly, but
      * doing something like {@code DATE_TRUNC(1 YEAR, NOW() - 1970-01-01T00:00:00Z)} is
      * much more sensible. But just grouping on {@code NOW()} is enough to test this.
      * <p>
@@ -1221,11 +1221,11 @@ public void testComplexFieldNames() throws IOException {
      * </p>
      */
     public void testInlineStatsNow() throws IOException {
-        assumeTrue("INLINESTATS only available on snapshots", Build.current().isSnapshot());
+        assumeTrue("INLINE STATS only available on snapshots", Build.current().isSnapshot());
         indexTimestampData(1);
 
         RequestObjectBuilder builder = requestObjectBuilder().query(
-            fromIndex() + " | EVAL now=NOW() | INLINESTATS AVG(value) BY now | SORT value ASC"
+            fromIndex() + " | EVAL now=NOW() | INLINE STATS AVG(value) BY now | SORT value ASC"
         );
         Map<String, Object> result = runEsql(builder);
         ListMatcher values = matchesList();

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/RestEsqlTestCase.java

@@ -688,15 +688,16 @@ emp_no:integer | job_positions:keyword | _fork:keyword
 10087          | Junior Developer      | fork2
 ;
 
-// INLINESTATS is under development, we enable this once it will be available
+// INLINE STATS is under development, we enable this once it will be available
 forkBeforeInlineStats-Ignore
 required_capability: fork_v9
+required_capability: inline_stats
 
 FROM employees
 | KEEP emp_no, languages, gender
 | FORK (WHERE emp_no == 10048 OR emp_no == 10081)
        (WHERE emp_no == 10081 OR emp_no == 10087)
-| INLINESTATS max_lang = MAX(languages) BY gender 
+| INLINE STATS max_lang = MAX(languages) BY gender 
 | SORT emp_no, gender, _fork
 | LIMIT 5
 ;
@@ -705,16 +706,17 @@ emp_no:integer | languages:integer | _fork:keyword | max_lang:integer | gender:k
 1 | 2 | 3 | 4 | 5
 ;
 
-// INLINESTATS is under development, we enable this once it will be available
+// INLINE STATS is under development, we enable this once it will be available
 forkBranchWithInlineStats-Ignore
 required_capability: fork_v9
+required_capability: inline_stats
 
 FROM employees
 | KEEP emp_no, languages, gender
 | FORK (WHERE emp_no == 10048 OR emp_no == 10081
-        | INLINESTATS x = MAX(languages) BY gender)
+        | INLINE STATS x = MAX(languages) BY gender)
        (WHERE emp_no == 10081 OR emp_no == 10087
-        | INLINESTATS x = MIN(languages))
+        | INLINE STATS x = MIN(languages))
         (WHERE emp_no == 10012 OR emp_no == 10012)
 | SORT emp_no, gender, _fork
 ;
@@ -727,13 +729,14 @@ emp_no:integer | languages:integer | x:integer | gender:keyword | _fork:keyword
 10087          | 5                 | 2         | F              | fork2
 ;
 
-// INLINESTATS is under development, we enable this once it will be available
+// INLINE STATS is under development, we enable this once it will be available
 forkAfterInlineStats-Ignore
 required_capability: fork_v9
+required_capability: inline_stats
 
 FROM employees
 | KEEP emp_no, languages, gender
-| INLINESTATS max_lang = MAX(languages) BY gender 
+| INLINE STATS max_lang = MAX(languages) BY gender 
 | FORK (WHERE emp_no == 10048 OR emp_no == 10081)
        (WHERE emp_no == 10081 OR emp_no == 10087)
 | SORT emp_no, gender, _fork