SHOW Statement for Metadata

SHOW command can be used to get brief system information. To get details about metatadata, information, and status in the system, please use select to query the tables in database INFORMATION_SCHEMA.

SHOW APPS

  1. SHOW APPS;

Shows all clients (such as applications) that connect to the cluster.

SHOW CLUSTER

  1. SHOW CLUSTER;

Shows information about the current cluster.

SHOW CONNECTIONS

  1. SHOW CONNECTIONS;

Shows information about connections to the system.

SHOW CONSUMERS

  1. SHOW CONSUMERS;

Shows information about all active consumers in the system.

SHOW CREATE DATABASE

  1. SHOW CREATE DATABASE db_name;

Shows the SQL statement used to create the specified database.

SHOW CREATE STABLE

  1. SHOW CREATE STABLE [db_name.]stb_name;

Shows the SQL statement used to create the specified supertable.

SHOW CREATE TABLE

  1. SHOW CREATE TABLE [db_name.]tb_name

Shows the SQL statement used to create the specified table. This statement can be used on supertables, standard tables, and subtables.

SHOW DATABASES

  1. SHOW DATABASES;

Shows all user-created databases.

SHOW DNODES

  1. SHOW DNODES;

Shows all dnodes in the system.

SHOW FUNCTIONS

  1. SHOW FUNCTIONS;

Shows all user-defined functions in the system.

SHOW LICENSE

  1. SHOW LICENSE;
  2. SHOW GRANTS;

Shows information about the TDengine Enterprise Edition license.

Note: TDengine Enterprise Edition only.

SHOW INDEXES

  1. SHOW INDEXES FROM tbl_name [FROM db_name];

Shows indices that have been created.

SHOW LOCAL VARIABLES

  1. SHOW LOCAL VARIABLES;

Shows the working configuration of the client.

SHOW MNODES

  1. SHOW MNODES;

Shows information about mnodes in the system.

SHOW QNODES

  1. SHOW QNODES;

Shows information about qnodes in the system.

SHOW SCORES

  1. SHOW SCORES;

Shows information about the storage space allowed by the license.

Note: TDengine Enterprise Edition only.

SHOW STABLES

  1. SHOW [db_name.]STABLES [LIKE 'pattern'];

Shows all supertables in the current database. You can use LIKE for fuzzy matching.

SHOW STREAMS

  1. SHOW STREAMS;

Shows information about streams in the system.

SHOW SUBSCRIPTIONS

  1. SHOW SUBSCRIPTIONS;

Shows all subscriptions in the system.

SHOW TABLES

  1. SHOW [db_name.]TABLES [LIKE 'pattern'];

Shows all standard tables and subtables in the current database. You can use LIKE for fuzzy matching.

SHOW TABLE DISTRIBUTED

  1. 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.

  1. show table distributed d0\G;

Show Example

  1. *************************** 1.row *************************** _block_dist: Total_Blocks=[5] Total_Size=[93.65 Kb] Average_size=[18.73 Kb] Compression_Ratio=[23.98 %]Total_Blocks :  Table d0 contains total 5 blocksTotal_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 KBCompression_Ratio: The data compression rate is 23.98%*** 2.row ***
  2. _block_dist: Total_Rows=[20000] Inmem_Rows=[0] MinRows=[3616] MaxRows=[4096] Average_Rows=[4000]Total_Rows: Table d0 contains 20,000 rowsInmem_Rows： The rows still in memory, i.e. not committed in disk, is 0, i.e. none such rowsMinRows：  The minimum number of rows in a block is 3,616 MaxRows： The maximum number of rows in a block is 4,096BAverage_Rows： The average number of rows in a block is 4,000*** 3.row ***
  3. _block_dist: Total_Tables=[1] Total_Files=[2]Total_Tables:  The number of child tables, 1 in this exampleTotal_Files：   The number of files storing the table's data, 2 in this example*** 4.row ***_block_dist: --------------------------------------------------------------------------------*** 5.row ***_block_dist: 0100 |*** 6.row ***_block_dist: 0299 |*** 7.row ***_block_dist: 0498 |*** 8.row ***_block_dist: 0697 |*** 9.row ***_block_dist: 0896 |*** 10.row ***_block_dist: 1095 |*** 11.row ***_block_dist: 1294 |*** 12.row ***_block_dist: 1493 |*** 13.row ***_block_dist: 1692 |*** 14.row ***_block_dist: 1891 |*** 15.row ***_block_dist: 2090 |*** 16.row ***_block_dist: 2289 |*** 17.row ***_block_dist: 2488 |*** 18.row ***_block_dist: 2687 |*** 19.row ***_block_dist: 2886 |*** 20.row ***_block_dist: 3085 |*** 21.row ***_block_dist: 3284 |*** 22.row ***_block_dist: 3483 |||||||||||||||||  1 (20.00%)*** 23.row ***_block_dist: 3682 |*** 24.row ***_block_dist: 3881 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||  4 (80.00%)Query OK, 24 row(s) in set (0.002444s)

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:

  • _block_dist: 3483 ||||||||||||||||| 1 (20.00%) means there is one block whose rows is between 3,483 and 3,681.
  • _block_dist: 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.

SHOW TAGS

  1. SHOW TAGS FROM child_table_name [FROM db_name];

Shows all tag information in a subtable.

SHOW TOPICS

  1. SHOW TOPICS;

Shows all topics in the current database.

SHOW TRANSACTIONS

  1. SHOW TRANSACTIONS;

Shows all running transactions in the system.

SHOW USERS

  1. SHOW USERS;

Shows information about users on the system. This includes user-created users and system-defined users.

SHOW VARIABLES

  1. SHOW VARIABLES;
  2. 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.

SHOW VGROUPS

  1. SHOW [db_name.]VGROUPS;

Shows information about all vgroups in the system or about the vgroups for a specified database.

SHOW VNODES

  1. SHOW VNODES [dnode_name];

Shows information about all vnodes in the system or about the vnodes for a specified dnode.