SHOW Statements 

SHOW CREATE TABLE 

SHOW CREATE [TEMPORARY] [TABLE|DICTIONARY|VIEW] [db.]table|view [INTO OUTFILE filename] [FORMAT format]

Returns a single String-type ‘statement’ column, which contains a single value – the CREATE query used for creating the specified object.

SHOW DATABASES 

Prints a list of all databases.

SHOW DATABASES [LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE filename] [FORMAT format]

This statement is identical to the query:

SELECT name FROM system.databases [WHERE name LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE filename] [FORMAT format]

Examples 

Getting database names, containing the symbols sequence 'de' in their names:

SHOW DATABASES LIKE '%de%'

Result:

┌─name────┐
│ default │
└─────────┘

Getting database names, containing symbols sequence 'de' in their names, in the case insensitive manner:

SHOW DATABASES ILIKE '%DE%'

Result:

┌─name────┐
│ default │
└─────────┘

Getting database names, not containing the symbols sequence 'de' in their names:

SHOW DATABASES NOT LIKE '%de%'

Result:

┌─name───────────────────────────┐
│ _temporary_and_external_tables │
│ system                         │
│ test                           │
│ tutorial                       │
└────────────────────────────────┘

Getting the first two rows from database names:

SHOW DATABASES LIMIT 2

Result:

┌─name───────────────────────────┐
│ _temporary_and_external_tables │
│ default                        │
└────────────────────────────────┘

See Also 

SHOW PROCESSLIST 

SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]

Outputs the content of the system.processes table, that contains a list of queries that is being processed at the moment, excepting SHOW PROCESSLIST queries.

The SELECT * FROM system.processes query returns data about all the current queries.

Tip (execute in the console):

$ watch -n1 "clickhouse-client --query='SHOW PROCESSLIST'"

SHOW TABLES 

Displays a list of tables.

SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]

If the FROM clause is not specified, the query returns the list of tables from the current database.

This statement is identical to the query:

SELECT name FROM system.tables [WHERE name LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]

Examples 

Getting table names, containing the symbols sequence 'user' in their names:

SHOW TABLES FROM system LIKE '%user%'

Result:

┌─name─────────────┐
│ user_directories │
│ users            │
└──────────────────┘

Getting table names, containing sequence 'user' in their names, in the case insensitive manner:

SHOW TABLES FROM system ILIKE '%USER%'

Result:

┌─name─────────────┐
│ user_directories │
│ users            │
└──────────────────┘

Getting table names, not containing the symbol sequence 's' in their names:

SHOW TABLES FROM system NOT LIKE '%s%'

Result:

┌─name─────────┐
│ metric_log   │
│ metric_log_0 │
│ metric_log_1 │
└──────────────┘

Getting the first two rows from table names:

SHOW TABLES FROM system LIMIT 2

Result:

┌─name───────────────────────────┐
│ aggregate_function_combinators │
│ asynchronous_metric_log        │
└────────────────────────────────┘

See Also 

SHOW DICTIONARIES 

Displays a list of external dictionaries.

SHOW DICTIONARIES [FROM <db>] [LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]

If the FROM clause is not specified, the query returns the list of dictionaries from the current database.

You can get the same results as the SHOW DICTIONARIES query in the following way:

SELECT name FROM system.dictionaries WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]

Example

The following query selects the first two rows from the list of tables in the system database, whose names contain reg.

SHOW DICTIONARIES FROM db LIKE '%reg%' LIMIT 2
┌─name─────────┐
│ regions      │
│ region_names │
└──────────────┘

SHOW GRANTS 

Shows privileges for a user.

Syntax 

SHOW GRANTS [FOR user1 [, user2 ...]]

If user is not specified, the query returns privileges for the current user.

SHOW CREATE USER 

Shows parameters that were used at a user creation.

SHOW CREATE USER does not output user passwords.

Syntax 

SHOW CREATE USER [name1 [, name2 ...] | CURRENT_USER]

SHOW CREATE ROLE 

Shows parameters that were used at a role creation.

Syntax 

SHOW CREATE ROLE name1 [, name2 ...]

SHOW CREATE ROW POLICY 

Shows parameters that were used at a row policy creation.

Syntax 

SHOW CREATE [ROW] POLICY name ON [database1.]table1 [, [database2.]table2 ...]

SHOW CREATE QUOTA 

Shows parameters that were used at a quota creation.

Syntax 

SHOW CREATE QUOTA [name1 [, name2 ...] | CURRENT]

SHOW CREATE SETTINGS PROFILE 

Shows parameters that were used at a settings profile creation.

Syntax 

SHOW CREATE [SETTINGS] PROFILE name1 [, name2 ...]

SHOW USERS 

Returns a list of user account names. To view user accounts parameters, see the system table system.users.

Syntax 

SHOW USERS

SHOW ROLES 

Returns a list of roles. To view another parameters, see system tables system.roles and system.role-grants.

Syntax 

SHOW [CURRENT|ENABLED] ROLES

SHOW PROFILES 

Returns a list of setting profiles. To view user accounts parameters, see the system table settings_profiles.

Syntax 

SHOW [SETTINGS] PROFILES

SHOW POLICIES 

Returns a list of row policies for the specified table. To view user accounts parameters, see the system table system.row_policies.

Syntax 

SHOW [ROW] POLICIES [ON [db.]table]

SHOW QUOTAS 

Returns a list of quotas. To view quotas parameters, see the system table system.quotas.

Syntax 

SHOW QUOTAS

SHOW QUOTA 

Returns a quota consumption for all users or for current user. To view another parameters, see system tables system.quotas_usage and system.quota_usage.

Syntax 

SHOW [CURRENT] QUOTA

SHOW ACCESS 

Shows all users, roles, profiles, etc. and all their grants.

Syntax 

SHOW ACCESS

SHOW CLUSTER(s) 

Returns a list of clusters. All available clusters are listed in the system.clusters table.

Syntax 

SHOW CLUSTER '<name>'
SHOW CLUSTERS [LIKE|NOT LIKE '<pattern>'] [LIMIT <N>]

Examples 

Query:

SHOW CLUSTERS;

Result:

┌─cluster──────────────────────────────────────┐
│ test_cluster_two_shards                      │
│ test_cluster_two_shards_internal_replication │
│ test_cluster_two_shards_localhost            │
│ test_shard_localhost                         │
│ test_shard_localhost_secure                  │
│ test_unavailable_shard                       │
└──────────────────────────────────────────────┘

Query:

SHOW CLUSTERS LIKE 'test%' LIMIT 1;

Result:

┌─cluster─────────────────┐
│ test_cluster_two_shards │
└─────────────────────────┘

Query:

SHOW CLUSTER 'test_shard_localhost' FORMAT Vertical;

Result:

Row 1:
──────
cluster:                 test_shard_localhost
shard_num:               1
shard_weight:            1
replica_num:             1
host_name:               localhost
host_address:            127.0.0.1
port:                    9000
is_local:                1
user:                    default
default_database:
errors_count:            0
estimated_recovery_time: 0

SHOW SETTINGS 

Returns a list of system settings and their values. Selects data from the system.settings table.

Syntax

SHOW [CHANGED] SETTINGS LIKE|ILIKE <name>

Clauses

LIKE|ILIKE allow to specify a matching pattern for the setting name. It can contain globs such as % or _. LIKE clause is case-sensitive, ILIKE — case insensitive.

When the CHANGED clause is used, the query returns only settings changed from their default values.

Examples

Query with the LIKE clause:

SHOW SETTINGS LIKE 'send_timeout';

Result:

┌─name─────────┬─type────┬─value─┐
│ send_timeout │ Seconds │ 300   │
└──────────────┴─────────┴───────┘

Query with the ILIKE clause:

SHOW SETTINGS ILIKE '%CONNECT_timeout%'

Result:

┌─name────────────────────────────────────┬─type─────────┬─value─┐
│ connect_timeout                         │ Seconds      │ 10    │
│ connect_timeout_with_failover_ms        │ Milliseconds │ 50    │
│ connect_timeout_with_failover_secure_ms │ Milliseconds │ 100   │
└─────────────────────────────────────────┴──────────────┴───────┘

Query with the CHANGED clause:

SHOW CHANGED SETTINGS ILIKE '%MEMORY%'

Result:

┌─name─────────────┬─type───┬─value───────┐
│ max_memory_usage │ UInt64 │ 10000000000 │
└──────────────────┴────────┴─────────────┘

See Also

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