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# Management Statements

## 1.  Status Inspection

### 1.1 View Current Tree/Table Model

**Syntax:**

```SQL
showCurrentSqlDialectStatement
    : SHOW CURRENT_SQL_DIALECT
    ;
```

**Example:**

```SQL
IoTDB> SHOW CURRENT_SQL_DIALECT
+-----------------+
|CurrentSqlDialect|
+-----------------+
|            TABLE|
+-----------------+
```

### 1.2 View Current User

**Syntax:**

```SQL
showCurrentUserStatement
    : SHOW CURRENT_USER
    ;
```

**Example:**

```SQL
IoTDB> SHOW CURRENT_USER
+-----------+
|CurrentUser|
+-----------+
|       root|
+-----------+
```

### 1.3 View Connected Database

**Syntax:**

```SQL
showCurrentDatabaseStatement
    : SHOW CURRENT_DATABASE
    ;
```

**Example:**

```SQL
IoTDB> SHOW CURRENT_DATABASE;
+---------------+
|CurrentDatabase|
+---------------+
|           null|
+---------------+

IoTDB> USE test;

IoTDB> SHOW CURRENT_DATABASE;
+---------------+
|CurrentDatabase|
+---------------+
|           test|
+---------------+
```

### 1.4 View Cluster Version

**Syntax:**

```SQL
showVersionStatement
    : SHOW VERSION
    ;
```

**Example:**

```SQL
IoTDB> SHOW VERSION
+-------+---------+
|Version|BuildInfo|
+-------+---------+
|2.0.1.2|  1ca4008|
+-------+---------+
```

### 1.5 View Key Cluster Parameters

**Syntax:**

```SQL
showVariablesStatement
    : SHOW VARIABLES
    ;
```

**Example:**

```SQL
IoTDB> SHOW VARIABLES
+----------------------------------+-----------------------------------------------------------------+
|                          Variable|                                                            Value|
+----------------------------------+-----------------------------------------------------------------+
|                       ClusterName|                                                   defaultCluster|
|             DataReplicationFactor|                                                                1|
|           SchemaReplicationFactor|                                                                1|
|  DataRegionConsensusProtocolClass|                      org.apache.iotdb.consensus.iot.IoTConsensus|
|SchemaRegionConsensusProtocolClass|                  org.apache.iotdb.consensus.ratis.RatisConsensus|
|  ConfigNodeConsensusProtocolClass|                  org.apache.iotdb.consensus.ratis.RatisConsensus|
|               TimePartitionOrigin|                                                                0|
|             TimePartitionInterval|                                                        604800000|
|              ReadConsistencyLevel|                                                           strong|
|           SchemaRegionPerDataNode|                                                                1|
|             DataRegionPerDataNode|                                                                0|
|                     SeriesSlotNum|                                                             1000|
|           SeriesSlotExecutorClass|org.apache.iotdb.commons.partition.executor.hash.BKDRHashExecutor|
|         DiskSpaceWarningThreshold|                                                             0.05|
|                TimestampPrecision|                                                               ms|
+----------------------------------+-----------------------------------------------------------------+
```

### 1.6 View Cluster ID

**Syntax:**

```SQL
showClusterIdStatement
    : SHOW (CLUSTERID | CLUSTER_ID)
    ;
```

**Example:**

```SQL
IoTDB> SHOW CLUSTER_ID
+------------------------------------+
|                           ClusterId|
+------------------------------------+
|40163007-9ec1-4455-aa36-8055d740fcda|
```

### 1.7  View Server Time

Shows time of the DataNode server directly connected to client

**Syntax:**

```SQL
showCurrentTimestampStatement
    : SHOW CURRENT_TIMESTAMP
    ;
```

**Example:**

```SQL
IoTDB> SHOW CURRENT_TIMESTAMP
+-----------------------------+
|             CurrentTimestamp|
+-----------------------------+
|2025-02-17T11:11:52.987+08:00|
+-----------------------------+
```

## 2. Status Configuration

### 2.1 Set Connection Tree/Table Model

**Syntax:**

```SQL
SET SQL_DIALECT EQ (TABLE | TREE)
```

**Example:**

```SQL
IoTDB> SET SQL_DIALECT=TABLE
IoTDB> SHOW CURRENT_SQL_DIALECT
+-----------------+
|CurrentSqlDialect|
+-----------------+
|            TABLE|
+-----------------+
```

### 2.2 Update Configuration Items

**Syntax:**

```SQL
setConfigurationStatement
    : SET CONFIGURATION propertyAssignments (ON INTEGER_VALUE)?
    ;

propertyAssignments
    : property (',' property)*
    ;
    
property
    : identifier EQ propertyValue
    ;

propertyValue
    : DEFAULT
    | expression
    ;
```

**Example:**

```SQL
IoTDB> SET CONFIGURATION disk_space_warning_threshold='0.05',heartbeat_interval_in_ms='1000' ON 1;
```

### 2.3 Load Manually Modified Configuration

**Syntax:**

```SQL
loadConfigurationStatement
    : LOAD CONFIGURATION localOrClusterMode?
    ;
    
localOrClusterMode
    : (ON (LOCAL | CLUSTER))
    ;
```

**Example:**

```SQL
IoTDB> LOAD CONFIGURATION ON LOCAL;
```

### 2.4 Set System Status

**Syntax:**

```SQL
setSystemStatusStatement
    : SET SYSTEM TO (READONLY | RUNNING) localOrClusterMode?
    ;    
    
localOrClusterMode
    : (ON (LOCAL | CLUSTER))
    ;
```

**Example:**

```SQL
IoTDB> SET SYSTEM TO READONLY ON CLUSTER;
```

## 3. Data Management

### 3.1 Flush Memory Table to Disk

**Syntax:**

```SQL
flushStatement
    : FLUSH identifier? (',' identifier)* booleanValue? localOrClusterMode?
    ;

booleanValue
    : TRUE | FALSE
    ;

localOrClusterMode
    : (ON (LOCAL | CLUSTER))
    ;
```

**Example:**

```SQL
IoTDB> FLUSH test_db TRUE ON LOCAL;
```

### 3.2 Clear DataNode Cache

**Syntax:**

```SQL
clearCacheStatement
    : CLEAR clearCacheOptions? CACHE localOrClusterMode?
    ;

clearCacheOptions
    : ATTRIBUTE
    | QUERY
    | ALL
    ;

localOrClusterMode
    : (ON (LOCAL | CLUSTER))
    ;
```

**Example:**

```SQL
IoTDB> CLEAR ALL CACHE ON LOCAL;
```

## 4. Data Repair

### 4.1 Start Background TsFile Repair

**Syntax:**

```SQL
startRepairDataStatement
    : START REPAIR DATA localOrClusterMode?
    ;
    
localOrClusterMode
    : (ON (LOCAL | CLUSTER))
    ;
```

**Example:**

```SQL
IoTDB> START REPAIR DATA ON CLUSTER;
```

### 4.2 Pause TsFile Repair

**Syntax:**

```SQL
stopRepairDataStatement
    : STOP REPAIR DATA localOrClusterMode?
    ;
    
localOrClusterMode
    : (ON (LOCAL | CLUSTER))
    ;
```

**Example:**

```SQL
IoTDB> STOP REPAIR DATA ON CLUSTER;
```

## 5. Query Operations

### 5.1 View Active Queries

**Syntax:**

```SQL
showQueriesStatement
    : SHOW (QUERIES | QUERY PROCESSLIST)
        (WHERE where=booleanExpression)?
        (ORDER BY sortItem (',' sortItem)*)?
        limitOffsetClause
    ;
```

**Example:**

```SQL
IoTDB> SHOW QUERIES WHERE elapsed_time > 30 
+-----------------------+-----------------------------+-----------+------------+------------+----+
|               query_id|                   start_time|datanode_id|elapsed_time|   statement|user|
+-----------------------+-----------------------------+-----------+------------+------------+----+
|20250108_101015_00000_1|2025-01-08T18:10:15.935+08:00|          1|      32.283|show queries|root|
+-----------------------+-----------------------------+-----------+------------+------------+----+
```

### 5.2 Terminate Queries

**Syntax:**

```SQL
killQueryStatement
    : KILL (QUERY queryId=string | ALL QUERIES)
    ;
```

**Example:**

```SQL
IoTDB> KILL QUERY 20250108_101015_00000_1; -- teminate specific query
IoTDB> KILL ALL QUERIES; -- teminate all query
```

### 5.3 Query Performance Analysis

#### 5.3.1 View Execution Plan

**Syntax:**

```SQL
EXPLAIN <SELECT_STATEMENT>
```

Detailed syntax reference: [EXPLAIN STATEMENT](../User-Manual/Query-Performance-Analysis.md#_1-explain-statement)

**Example:**

```SQL
IoTDB> explain select * from t1
+-----------------------------------------------------------------------------------------------+
|                                                                              distribution plan|
+-----------------------------------------------------------------------------------------------+
|                        ┌─────────────────────────────────────────────┐                        |
|                        │OutputNode-4                                 │                        |
|                        │OutputColumns-[time, device_id, type, speed] │                        |
|                        │OutputSymbols: [time, device_id, type, speed]│                        |
|                        └─────────────────────────────────────────────┘                        |
|                                               │                                               |
|                                               │                                               |
|                        ┌─────────────────────────────────────────────┐                        |
|                        │Collect-21                                   │                        |
|                        │OutputSymbols: [time, device_id, type, speed]│                        |
|                        └─────────────────────────────────────────────┘                        |
|                       ┌───────────────────────┴───────────────────────┐                       |
|                       │                                               │                       |
|┌─────────────────────────────────────────────┐                  ┌───────────┐                 |
|│TableScan-19                                 │                  │Exchange-28│                 |
|│QualifiedTableName: test.t1                  │                  └───────────┘                 |
|│OutputSymbols: [time, device_id, type, speed]│                        │                       |
|│DeviceNumber: 1                              │                        │                       |
|│ScanOrder: ASC                               │ ┌─────────────────────────────────────────────┐|
|│PushDownOffset: 0                            │ │TableScan-20                                 │|
|│PushDownLimit: 0                             │ │QualifiedTableName: test.t1                  │|
|│PushDownLimitToEachDevice: false             │ │OutputSymbols: [time, device_id, type, speed]│|
|│RegionId: 2                                  │ │DeviceNumber: 1                              │|
|└─────────────────────────────────────────────┘ │ScanOrder: ASC                               │|
|                                                │PushDownOffset: 0                            │|
|                                                │PushDownLimit: 0                             │|
|                                                │PushDownLimitToEachDevice: false             │|
|                                                │RegionId: 1                                  │|
|                                                └─────────────────────────────────────────────┘|
+-----------------------------------------------------------------------------------------------+
```

#### 5.3.2 Analyze Query Performance

**Syntax:**

```SQL
EXPLAIN ANALYZE [VERBOSE] <SELECT_STATEMENT>
```

Detailed syntax reference: [EXPLAIN ANALYZE STATEMENT](../User-Manual/Query-Performance-Analysis.md#_2-explain-analyze-statement)

**Example:**

```SQL
IoTDB> explain analyze verbose select * from t1
+-----------------------------------------------------------------------------------------------+
|                                                                                Explain Analyze|
+-----------------------------------------------------------------------------------------------+
|Analyze Cost: 38.860 ms                                                                        |
|Fetch Partition Cost: 9.888 ms                                                                 |
|Fetch Schema Cost: 54.046 ms                                                                   |
|Logical Plan Cost: 10.102 ms                                                                   |
|Logical Optimization Cost: 17.396 ms                                                           |
|Distribution Plan Cost: 2.508 ms                                                               |
|Dispatch Cost: 22.126 ms                                                                       |
|Fragment Instances Count: 2                                                                    |
|                                                                                               |
|FRAGMENT-INSTANCE[Id: 20241127_090849_00009_1.2.0][IP: 0.0.0.0][DataRegion: 2][State: FINISHED]|
|  Total Wall Time: 18 ms                                                                       |
|  Cost of initDataQuerySource: 6.153 ms                                                        |
|  Seq File(unclosed): 1, Seq File(closed): 0                                                   |
|  UnSeq File(unclosed): 0, UnSeq File(closed): 0                                               |
|  ready queued time: 0.164 ms, blocked queued time: 0.342 ms                                   |
|  Query Statistics:                                                                            |
|    loadBloomFilterFromCacheCount: 0                                                           |
|    loadBloomFilterFromDiskCount: 0                                                            |
|    loadBloomFilterActualIOSize: 0                                                             |
|    loadBloomFilterTime: 0.000                                                                 |
|    loadTimeSeriesMetadataAlignedMemSeqCount: 1                                                |
|    loadTimeSeriesMetadataAlignedMemSeqTime: 0.246                                             |
|    loadTimeSeriesMetadataFromCacheCount: 0                                                    |
|    loadTimeSeriesMetadataFromDiskCount: 0                                                     |
|    loadTimeSeriesMetadataActualIOSize: 0                                                      |
|    constructAlignedChunkReadersMemCount: 1                                                    |
|    constructAlignedChunkReadersMemTime: 0.294                                                 |
|    loadChunkFromCacheCount: 0                                                                 |
|    loadChunkFromDiskCount: 0                                                                  |
|    loadChunkActualIOSize: 0                                                                   |
|    pageReadersDecodeAlignedMemCount: 1                                                        |
|    pageReadersDecodeAlignedMemTime: 0.047                                                     |
|    [PlanNodeId 43]: IdentitySinkNode(IdentitySinkOperator)                                    |
|        CPU Time: 5.523 ms                                                                     |
|        output: 2 rows                                                                         |
|        HasNext() Called Count: 6                                                              |
|        Next() Called Count: 5                                                                 |
|        Estimated Memory Size: : 327680                                                        |
|      [PlanNodeId 31]: CollectNode(CollectOperator)                                            |
|          CPU Time: 5.512 ms                                                                   |
|          output: 2 rows                                                                       |
|          HasNext() Called Count: 6                                                            |
|          Next() Called Count: 5                                                               |
|          Estimated Memory Size: : 327680                                                      |
|        [PlanNodeId 29]: TableScanNode(TableScanOperator)                                      |
|            CPU Time: 5.439 ms                                                                 |
|            output: 1 rows                                                                     |
|            HasNext() Called Count: 3
|            Next() Called Count: 2                                                             |
|            Estimated Memory Size: : 327680                                                    |
|            DeviceNumber: 1                                                                    |
|            CurrentDeviceIndex: 0                                                              |
|        [PlanNodeId 40]: ExchangeNode(ExchangeOperator)                                        |
|            CPU Time: 0.053 ms                                                                 |
|            output: 1 rows                                                                     |
|            HasNext() Called Count: 2                                                          |
|            Next() Called Count: 1                                                             |
|            Estimated Memory Size: : 131072                                                    |
|                                                                                               |
|FRAGMENT-INSTANCE[Id: 20241127_090849_00009_1.3.0][IP: 0.0.0.0][DataRegion: 1][State: FINISHED]|
|  Total Wall Time: 13 ms                                                                       |
|  Cost of initDataQuerySource: 5.725 ms                                                        |
|  Seq File(unclosed): 1, Seq File(closed): 0                                                   |
|  UnSeq File(unclosed): 0, UnSeq File(closed): 0                                               |
|  ready queued time: 0.118 ms, blocked queued time: 5.844 ms                                   |
|  Query Statistics:                                                                            |
|    loadBloomFilterFromCacheCount: 0                                                           |
|    loadBloomFilterFromDiskCount: 0                                                            |
|    loadBloomFilterActualIOSize: 0                                                             |
|    loadBloomFilterTime: 0.000                                                                 |
|    loadTimeSeriesMetadataAlignedMemSeqCount: 1                                                |
|    loadTimeSeriesMetadataAlignedMemSeqTime: 0.004                                             |
|    loadTimeSeriesMetadataFromCacheCount: 0                                                    |
|    loadTimeSeriesMetadataFromDiskCount: 0                                                     |
|    loadTimeSeriesMetadataActualIOSize: 0                                                      |
|    constructAlignedChunkReadersMemCount: 1                                                    |
|    constructAlignedChunkReadersMemTime: 0.001                                                 |
|    loadChunkFromCacheCount: 0                                                                 |
|    loadChunkFromDiskCount: 0                                                                  |
|    loadChunkActualIOSize: 0                                                                   |
|    pageReadersDecodeAlignedMemCount: 1                                                        |
|    pageReadersDecodeAlignedMemTime: 0.007                                                     |
|    [PlanNodeId 42]: IdentitySinkNode(IdentitySinkOperator)                                    |
|        CPU Time: 0.270 ms                                                                     |
|        output: 1 rows                                                                         |
|        HasNext() Called Count: 3                                                              |
|        Next() Called Count: 2                                                                 |
|        Estimated Memory Size: : 327680                                                        |
|      [PlanNodeId 30]: TableScanNode(TableScanOperator)                                        |
|          CPU Time: 0.250 ms                                                                   |
|          output: 1 rows                                                                       |
|          HasNext() Called Count: 3                                                            |
|          Next() Called Count: 2                                                               |
|          Estimated Memory Size: : 327680                                                      |
|          DeviceNumber: 1                                                                      |
|          CurrentDeviceIndex: 0                                                                |
+-----------------------------------------------------------------------------------------------+
```