[Feature] Support SHOW DATA SKEW stmt

docs/.vuepress/sidebar/en.js

@@ -433,6 +433,7 @@ module.exports = [
               "ADMIN SHOW CONFIG",
               "ADMIN SHOW REPLICA DISTRIBUTION",
               "ADMIN SHOW REPLICA STATUS",
+              "ADMIN-SHOW-DATA-SKEW",
               "ALTER CLUSTER",
               "ALTER SYSTEM",
               "CANCEL DECOMMISSION",

docs/.vuepress/sidebar/zh-CN.js

@@ -438,6 +438,7 @@ module.exports = [
               "ADMIN SHOW CONFIG",
               "ADMIN SHOW REPLICA DISTRIBUTION",
               "ADMIN SHOW REPLICA STATUS",
+              "ADMIN-SHOW-DATA-SKEW",
               "ALTER CLUSTER",
               "ALTER SYSTEM",
               "CANCEL DECOMMISSION",

docs/en/sql-reference/sql-statements/Administration/ADMIN-SHOW-DATA-SKEW.md

@@ -0,0 +1,50 @@
+---
+{
+    "title": "ADMIN SHOW DATA SKEW",
+    "language": "en"
+}
+---
+
+<!-- 
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# ADMIN SHOW DATA SKEW
+## description
+
+    This statement is used to view the data skew of a table or a partition.
+
+    grammar:
+
+        ADMIN SHOW DATA SKEW FROM [db_name.]tbl_name [PARTITION (p1)];
+
+	Description:
+
+		1. Only one partition must be specified. For non-partitioned tables, the partition name is the same as the table name.
+		2. The result will show the data volume of each bucket under the specified partition, and the proportion of the data volume of each bucket in the total data volume.
+
+## example
+
+    1. View the data skew of the table
+
+        ADMIN SHOW DATA SKEW FROM db1.test PARTITION(p1);
+
+## keyword
+
+    ADMIN, SHOW, DATA, SKEW
+

docs/zh-CN/sql-reference/sql-statements/Administration/ADMIN-SHOW-DATA-SKEW.md

@@ -0,0 +1,50 @@
+---
+{
+    "title": "ADMIN SHOW DATA SKEW",
+    "language": "zh-CN"
+}
+---
+
+<!-- 
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# ADMIN SHOW DATA SKEW
+## description
+
+    该语句用于查看表或某个分区的数据倾斜情况。
+
+    语法：
+
+        ADMIN SHOW DATA SKEW FROM [db_name.]tbl_name PARTITION (partition_name);
+
+    说明：
+
+        1. 必须指定且仅指定一个分区。对于非分区表，分区名称同表名。
+        2. 结果将展示指定分区下，各个分桶的数据量，以及每个分桶数据量在总数据量中的占比。
+
+## example
+
+    1. 查看表的数据倾斜情况
+
+        ADMIN SHOW DATA SKEW FROM db1.test PARTITION(p1);
+
+## keyword
+
+    ADMIN,SHOW,DATA,SKEW
+

fe/fe-core/src/main/cup/sql_parser.cup

@@ -262,6 +262,7 @@ terminal String KW_ADD, KW_ADMIN, KW_AFTER, KW_AGGREGATE, KW_ALL, KW_ALTER, KW_A
     KW_REPAIR, KW_REPEATABLE, KW_REPOSITORY, KW_REPOSITORIES, KW_REPLACE, KW_REPLACE_IF_NOT_NULL, KW_REPLICA, KW_RESOURCE, KW_RESOURCES, KW_RESTORE, KW_RETURNS, KW_RESUME, KW_REVOKE,
     KW_RIGHT, KW_ROLE, KW_ROLES, KW_ROLLBACK, KW_ROLLUP, KW_ROUTINE, KW_ROW, KW_ROWS,
     KW_S3, KW_SCHEMA, KW_SCHEMAS, KW_SECOND, KW_SELECT, KW_SEMI, KW_SERIALIZABLE, KW_SESSION, KW_SET, KW_SETS, KW_SET_VAR, KW_SHOW, KW_SIGNED,
+    KW_SKEW,
     KW_SMALLINT, KW_SNAPSHOT, KW_SONAME, KW_SPLIT, KW_START, KW_STATUS, KW_STOP, KW_STORAGE, KW_STREAM, KW_STRING, KW_STRUCT,
     KW_SUM, KW_SUPERUSER, KW_SYNC, KW_SYSTEM,
     KW_TABLE, KW_TABLES, KW_TABLET, KW_TASK, KW_TEMPORARY, KW_TERMINATED, KW_THAN, KW_TIME, KW_THEN, KW_TIMESTAMP, KW_TINYINT,
@@ -4823,6 +4824,10 @@ admin_stmt ::=
     {:
         RESULT = new AdminCheckTabletsStmt(tabletIds, properties);
     :}
+    | KW_ADMIN KW_SHOW KW_DATA KW_SKEW KW_FROM base_table_ref:table_ref
+    {:
+        RESULT = new AdminShowDataSkewStmt(table_ref);
+    :}
     ;
 
 truncate_stmt ::=
@@ -5132,6 +5137,8 @@ keyword ::=
     {: RESULT = id; :}
     | KW_SESSION:id
     {: RESULT = id; :}
+    | KW_SKEW:id
+    {: RESULT = id; :}
     | KW_SNAPSHOT:id
     {: RESULT = id; :}
     | KW_SONAME:id

fe/fe-core/src/main/java/org/apache/doris/analysis/AdminShowDataSkewStmt.java

@@ -0,0 +1,88 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package org.apache.doris.analysis;
+
+import org.apache.doris.catalog.Catalog;
+import org.apache.doris.catalog.Column;
+import org.apache.doris.catalog.ScalarType;
+import org.apache.doris.common.AnalysisException;
+import org.apache.doris.common.ErrorCode;
+import org.apache.doris.common.ErrorReport;
+import org.apache.doris.common.UserException;
+import org.apache.doris.mysql.privilege.PrivPredicate;
+import org.apache.doris.qe.ConnectContext;
+import org.apache.doris.qe.ShowResultSetMetaData;
+
+import com.google.common.collect.ImmutableList;
+
+// admin show data skew from tbl [partition(p1, p2, ...)]
+public class AdminShowDataSkewStmt extends ShowStmt {
+    public static final ImmutableList<String> TITLE_NAMES = new ImmutableList.Builder<String>()
+            .add("BucketIdx").add("AvgDataSize")
+            .add("Graph").add("Percent")
+            .build();
+
+    private TableRef tblRef;
+
+    public AdminShowDataSkewStmt(TableRef tblRef) {
+        this.tblRef = tblRef;
+    }
+
+    @Override
+    public void analyze(Analyzer analyzer) throws UserException {
+        super.analyze(analyzer);
+
+        // check auth
+        if (!Catalog.getCurrentCatalog().getAuth().checkGlobalPriv(ConnectContext.get(), PrivPredicate.ADMIN)) {
+            ErrorReport.reportAnalysisException(ErrorCode.ERR_SPECIFIC_ACCESS_DENIED_ERROR, "ADMIN");
+        }
+
+        tblRef.getName().analyze(analyzer);
+
+        PartitionNames partitionNames = tblRef.getPartitionNames();
+        if (partitionNames == null || partitionNames.getPartitionNames().size() != 1) {
+            throw new AnalysisException("Should specify one and only one partition");
+        }
+    }
+
+    public String getDbName() {
+        return tblRef.getName().getDb();
+    }
+
+    public String getTblName() {
+        return tblRef.getName().getTbl();
+    }
+
+    public PartitionNames getPartitionNames() {
+        return tblRef.getPartitionNames();
+    }
+
+    @Override
+    public ShowResultSetMetaData getMetaData() {
+        ShowResultSetMetaData.Builder builder = ShowResultSetMetaData.builder();
+        for (String title : TITLE_NAMES) {
+            builder.addColumn(new Column(title, ScalarType.createVarchar(30)));
+        }
+        return builder.build();
+    }
+
+    @Override
+    public RedirectStatus getRedirectStatus() {
+        return RedirectStatus.FORWARD_NO_SYNC;
+    }
+}

fe/fe-core/src/main/java/org/apache/doris/analysis/AdminShowReplicaDistributionStmt.java

@@ -35,7 +35,10 @@
 // admin show replica distribution from tbl [partition(p1, p2, ...)]
 public class AdminShowReplicaDistributionStmt extends ShowStmt {
     public static final ImmutableList<String> TITLE_NAMES = new ImmutableList.Builder<String>()
-            .add("BackendId").add("ReplicaNum").add("Graph").add("Percent").build();
+            .add("BackendId").add("ReplicaNum").add("ReplicaSize")
+            .add("NumGraph").add("NumPercent")
+            .add("SizeGraph").add("SizePercent")
+            .build();
 
     private TableRef tblRef;
 
@@ -88,10 +91,6 @@ public ShowResultSetMetaData getMetaData() {
 
     @Override
     public RedirectStatus getRedirectStatus() {
-        if (ConnectContext.get().getSessionVariable().getForwardToMaster()) {
-            return RedirectStatus.FORWARD_NO_SYNC;
-        } else {
-            return RedirectStatus.NO_FORWARD;
-        }
+        return RedirectStatus.FORWARD_NO_SYNC;
     }
 }