Project: TDengine (App Definition and Development / Database)
File: 24-show.md

title: SHOW Statement for Metadata sidebar_label: SHOW Statement description: This document describes how to use the SHOW statement in TDengine. `SHOW` command can be used to get brief system information. To get details about metadata, information, and status in the system, please use `select` to query the tables in database `INFORMATION_SCHEMA`. ```sql SHOW APPS; ``` Shows all clients (such as applications) that connect to the cluster. ```sql SHOW CLUSTER; ``` Shows information about the current cluster. ```sql SHOW CLUSTER ALIVE; ``` It is used to check whether the cluster is available or not. Return value: 0 means unavailable, 1 means available, 2 means partially available (some dnodes are offline, the other dnodes are available) ```sql SHOW CONNECTIONS; ``` Shows information about connections to the system. ```sql SHOW CONSUMERS; ``` Shows information about all consumers in the system. ```sql SHOW CREATE DATABASE db_name; ``` Shows the SQL statement used to create the specified database. ```sql SHOW CREATE STABLE [dbname.]stbname; ``` Shows the SQL statement used to create the specified supertable. ```sql SHOW CREATE TABLE [dbname.]tbname ``` Shows the SQL statement used to create the specified table. This statement can be used on supertables, standard tables, and subtables. ```sql SHOW [USER | SYSTEM] DATABASES; ``` Shows all databases. The `USER` qualifier specifies only user-created databases. The `SYSTEM` qualifier specifies only system databases. ```sql SHOW DNODES; ``` Shows all dnodes in the system. ```sql SHOW FUNCTIONS; ``` Shows all user-defined functions in the system. ```sql SHOW LICENCES; SHOW GRANTS; ``` Shows information about the TDengine Enterprise Edition license. Note: TDengine Enterprise Edition only. ```sql SHOW INDEXES FROM tblname [FROM dbname]; SHOW INDEXES FROM [dbname.]tblname; ``` Shows indices that have been created. ```sql SHOW LOCAL VARIABLES; ``` Shows the working configuration of the client. ```sql SHOW MNODES; ``` Shows information about mnodes in the system. ```sql SHOW QNODES; ``` Shows information about qnodes in the system. ```sql SHOW QUERIES; ``` Shows the queries in progress in the system. ```sql SHOW SCORES; ``` Shows information about the storage space allowed by the license. Note: TDengine Enterprise Edition only. ```sql SHOW [db_name.]STABLES [LIKE 'pattern']; ``` Shows all supertables in the current database. You can use LIKE for fuzzy matching. ```sql SHOW STREAMS; ``` Shows information about streams in the system. ```sql SHOW SUBSCRIPTIONS; ``` Shows all subscriptions in the system. ```sql SHOW [NORMAL | CHILD] [db_name.]TABLES [LIKE 'pattern']; ``` Shows all standard tables and subtables in the current database. You can use LIKE for fuzzy matching. The `Normal` qualifier specifies standard tables. The `CHILD` qualifier specifies subtables. ```sql SHOW TABLE DISTRIBUTED table_name; ``` Shows how table data is distributed. Examples: Below is an example of this command to display the block distribution of table `d0` in detailed format. ```sql show table distributed d0\G; ``` <details> <summary> Show Example </summary> <pre><code> 1.row * blockdist: TotalBlocks=[5] TotalSize=[93.65 KB] Averagesize=[18.73 KB]

%] Total_Blocks : Table `d0` contains total 5 blocks Total_Size: The total size of all the data blocks in table `d0` is 93.65 KB Average_size: The average size of each block is 18.73 KB Compression_Ratio: The data compression rate is 23.98% 2.row * blockdist: TotalRows=[20000] InmemRows=[0] MinRows=[3616] MaxRows=[4096] Average_Rows=[4000] Total_Rows: Table `d0` contains 20,000 rows Inmem_Rows: The rows still in memory, i.e. not committed in disk, is 0, i.e. none such rows MinRows: The minimum number of rows in a block is 3,616 MaxRows: The maximum number of rows in a block is 4,096B Average_Rows: The average number of rows in a block is 4,000 3.row * blockdist: TotalTables=[1] TotalFiles=[2] Total_Tables: The number of child tables, 1 in this example Total_Files: The number of files storing the table's data, 2 in this example 4.row * blockdist: -- 5.row * blockdist: 0100 | 6.row * blockdist: 0299 | 7.row * blockdist: 0498 | 8.row * blockdist: 0697 | 9.row * blockdist: 0896 | 10.row * blockdist: 1095 | 11.row * blockdist: 1294 | 12.row * blockdist: 1493 | 13.row * blockdist: 1692 | 14.row * blockdist: 1891 | 15.row * blockdist: 2090 | 16.row * blockdist: 2289 | 17.row * blockdist: 2488 | 18.row * blockdist: 2687 | 19.row * blockdist: 2886 | 20.row * blockdist: 3085 | 21.row * blockdist: 3284 | 22.row * blockdist: 3483 ||||||||||||||||| 1 (20.00%) 23.row * blockdist: 3682 | 24.row * blockdist: 3881 ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| 4 (80.00%) Query OK, 24 row(s) in set (0.002444s) </code></pre> </details> The above show the block distribution percentage according to the number of rows in each block. In the above example, we can get below information: `blockdist: 3483 ||||||||||||||||| 1 (20.00%)` means there is one block whose rows is between 3,483 and 3,681. `blockdist: 3881 ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| 4 (80.00%)` means there are 4 blocks whose rows is between 3,881 and 4,096. - The number of blocks whose rows fall in other range is zero. Note that only the information about the data blocks in the data file will be displayed here, and the information about the data in the stt file will not be displayed. ```sql SHOW TAGS FROM childtablename [FROM db_name]; SHOW TAGS FROM [dbname.]childtable_name; ``` Shows all tag information in a subtable. ```sql SHOW TOPICS; ``` Shows all topics in the current database. ```sql SHOW TRANSACTIONS; ``` Shows all running transactions in the system. ```sql SHOW USERS; ``` Shows information about users on the system. This includes user-created users and system-defined users. ```sql SHOW VARIABLES; SHOW DNODE dnode_id VARIABLES; ``` Shows the working configuration of the parameters that must be the same on each node. You can also specify a dnode to show the working configuration for that node. ```sql SHOW [db_name.]VGROUPS; ``` Shows information about all vgroups in the current database. ```sql SHOW VNODES [ON DNODE dnode_id]; ``` Shows information about all vnodes in the system or about the vnodes for a specified dnode.