语法：
showCurrentSqlDialectStatement : SHOW CURRENT_SQL_DIALECT ;
示例：
IoTDB> SHOW CURRENT_SQL_DIALECT +-----------------+ |CurrentSqlDialect| +-----------------+ | TABLE| +-----------------+
语法：
showCurrentUserStatement : SHOW CURRENT_USER ;
示例：
IoTDB> SHOW CURRENT_USER +-----------+ |CurrentUser| +-----------+ | root| +-----------+
语法：
showCurrentDatabaseStatement : SHOW CURRENT_DATABASE ;
示例：
IoTDB> SHOW CURRENT_DATABASE; +---------------+ |CurrentDatabase| +---------------+ | null| +---------------+ IoTDB> USE test; IoTDB> SHOW CURRENT_DATABASE; +---------------+ |CurrentDatabase| +---------------+ | test| +---------------+
语法：
showVersionStatement : SHOW VERSION ;
示例：
IoTDB> SHOW VERSION +-------+---------+ |Version|BuildInfo| +-------+---------+ |2.0.1.2| 1ca4008| +-------+---------+
语法：
showVariablesStatement : SHOW VARIABLES ;
示例：
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| +----------------------------------+-----------------------------------------------------------------+
语法：
showClusterIdStatement : SHOW (CLUSTERID | CLUSTER_ID) ;
示例：
IoTDB> SHOW CLUSTER_ID +------------------------------------+ | ClusterId| +------------------------------------+ |40163007-9ec1-4455-aa36-8055d740fcda|
查看客户端直连的 DataNode 进程所在的服务器的时间
语法：
showCurrentTimestampStatement : SHOW CURRENT_TIMESTAMP ;
示例：
IoTDB> SHOW CURRENT_TIMESTAMP +-----------------------------+ | CurrentTimestamp| +-----------------------------+ |2025-02-17T11:11:52.987+08:00| +-----------------------------+
语法：
SET SQL_DIALECT EQ (TABLE | TREE)
示例：
IoTDB> SET SQL_DIALECT=TABLE IoTDB> SHOW CURRENT_SQL_DIALECT +-----------------+ |CurrentSqlDialect| +-----------------+ | TABLE| +-----------------+
语法：
setConfigurationStatement : SET CONFIGURATION propertyAssignments (ON INTEGER_VALUE)? ; propertyAssignments : property (',' property)* ; property : identifier EQ propertyValue ; propertyValue : DEFAULT | expression ;
示例：
IoTDB> SET CONFIGURATION disk_space_warning_threshold='0.05',heartbeat_interval_in_ms='1000' ON 1;
语法：
loadConfigurationStatement : LOAD CONFIGURATION localOrClusterMode? ; localOrClusterMode : (ON (LOCAL | CLUSTER)) ;
示例：
IoTDB> LOAD CONFIGURATION ON LOCAL;
语法：
setSystemStatusStatement : SET SYSTEM TO (READONLY | RUNNING) localOrClusterMode? ; localOrClusterMode : (ON (LOCAL | CLUSTER)) ;
示例：
IoTDB> SET SYSTEM TO READONLY ON CLUSTER;
语法：
flushStatement : FLUSH identifier? (',' identifier)* booleanValue? localOrClusterMode? ; booleanValue : TRUE | FALSE ; localOrClusterMode : (ON (LOCAL | CLUSTER)) ;
示例：
IoTDB> FLUSH test_db TRUE ON LOCAL;
语法：
clearCacheStatement : CLEAR clearCacheOptions? CACHE localOrClusterMode? ; clearCacheOptions : ATTRIBUTE | QUERY | ALL ; localOrClusterMode : (ON (LOCAL | CLUSTER)) ;
示例：
IoTDB> CLEAR ALL CACHE ON LOCAL;
语法：
startRepairDataStatement : START REPAIR DATA localOrClusterMode? ; localOrClusterMode : (ON (LOCAL | CLUSTER)) ;
示例：
IoTDB> START REPAIR DATA ON CLUSTER;
语法：
stopRepairDataStatement : STOP REPAIR DATA localOrClusterMode? ; localOrClusterMode : (ON (LOCAL | CLUSTER)) ;
示例：
IoTDB> STOP REPAIR DATA ON CLUSTER;
语法：
showQueriesStatement : SHOW (QUERIES | QUERY PROCESSLIST) (WHERE where=booleanExpression)? (ORDER BY sortItem (',' sortItem)*)? limitOffsetClause ;
示例：
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| +-----------------------+-----------------------------+-----------+------------+------------+----+
语法：
killQueryStatement : KILL (QUERY queryId=string | ALL QUERIES) ;
示例：
IoTDB> KILL QUERY 20250108_101015_00000_1; -- 终止指定query IoTDB> KILL ALL QUERIES; -- 终止所有query
语法：
EXPLAIN <SELECT_STATEMENT>
更多详细语法说明请参考：EXPLAIN 语句
示例：
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 │| | └─────────────────────────────────────────────┘| +-----------------------------------------------------------------------------------------------+
语法：
EXPLAIN ANALYZE [VERBOSE] <SELECT_STATEMENT>
更多详细语法说明请参考：EXPLAIN ANALYZE 语句
示例：
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 | +-----------------------------------------------------------------------------------------------+