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13 KiB
Markdown
515 lines
13 KiB
Markdown
---
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slug: /en/sql-reference/statements/show
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sidebar_position: 37
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sidebar_label: SHOW
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---
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# SHOW Statements
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## SHOW CREATE TABLE
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``` sql
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SHOW CREATE [TEMPORARY] [TABLE|DICTIONARY|VIEW] [db.]table|view [INTO OUTFILE filename] [FORMAT format]
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```
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Returns a single `String`-type ‘statement’ column, which contains a single value – the `CREATE` query used for creating the specified object.
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Note that if you use this statement to get `CREATE` query of system tables, you will get a *fake* query, which only declares table structure, but cannot be used to create table.
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## SHOW DATABASES
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Prints a list of all databases.
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```sql
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SHOW DATABASES [LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE filename] [FORMAT format]
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```
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This statement is identical to the query:
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```sql
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SELECT name FROM system.databases [WHERE name LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE filename] [FORMAT format]
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```
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### Examples
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Getting database names, containing the symbols sequence 'de' in their names:
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``` sql
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SHOW DATABASES LIKE '%de%'
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```
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Result:
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``` text
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┌─name────┐
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│ default │
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└─────────┘
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```
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Getting database names, containing symbols sequence 'de' in their names, in the case insensitive manner:
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``` sql
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SHOW DATABASES ILIKE '%DE%'
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```
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Result:
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``` text
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┌─name────┐
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│ default │
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└─────────┘
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```
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Getting database names, not containing the symbols sequence 'de' in their names:
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``` sql
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SHOW DATABASES NOT LIKE '%de%'
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```
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Result:
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``` text
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┌─name───────────────────────────┐
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│ _temporary_and_external_tables │
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│ system │
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│ test │
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│ tutorial │
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└────────────────────────────────┘
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```
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Getting the first two rows from database names:
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``` sql
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SHOW DATABASES LIMIT 2
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```
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Result:
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``` text
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┌─name───────────────────────────┐
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│ _temporary_and_external_tables │
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│ default │
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└────────────────────────────────┘
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```
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### See Also
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- [CREATE DATABASE](https://clickhouse.com/docs/en/sql-reference/statements/create/database/#query-language-create-database)
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## SHOW PROCESSLIST
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``` sql
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SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]
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```
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Outputs the content of the [system.processes](../../operations/system-tables/processes.md#system_tables-processes) table, that contains a list of queries that is being processed at the moment, excepting `SHOW PROCESSLIST` queries.
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The `SELECT * FROM system.processes` query returns data about all the current queries.
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Tip (execute in the console):
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``` bash
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$ watch -n1 "clickhouse-client --query='SHOW PROCESSLIST'"
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```
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## SHOW TABLES
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Displays a list of tables.
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```sql
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SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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If the `FROM` clause is not specified, the query returns the list of tables from the current database.
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This statement is identical to the query:
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```sql
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SELECT name FROM system.tables [WHERE name LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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### Examples
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Getting table names, containing the symbols sequence 'user' in their names:
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``` sql
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SHOW TABLES FROM system LIKE '%user%'
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```
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Result:
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``` text
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┌─name─────────────┐
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│ user_directories │
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│ users │
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└──────────────────┘
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```
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Getting table names, containing sequence 'user' in their names, in the case insensitive manner:
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``` sql
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SHOW TABLES FROM system ILIKE '%USER%'
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```
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Result:
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``` text
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┌─name─────────────┐
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│ user_directories │
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│ users │
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└──────────────────┘
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```
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Getting table names, not containing the symbol sequence 's' in their names:
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``` sql
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SHOW TABLES FROM system NOT LIKE '%s%'
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```
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Result:
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``` text
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┌─name─────────┐
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│ metric_log │
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│ metric_log_0 │
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│ metric_log_1 │
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└──────────────┘
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```
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Getting the first two rows from table names:
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``` sql
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SHOW TABLES FROM system LIMIT 2
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```
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Result:
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``` text
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┌─name───────────────────────────┐
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│ aggregate_function_combinators │
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│ asynchronous_metric_log │
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└────────────────────────────────┘
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```
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### See Also
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- [Create Tables](https://clickhouse.com/docs/en/getting-started/tutorial/#create-tables)
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- [SHOW CREATE TABLE](https://clickhouse.com/docs/en/sql-reference/statements/show/#show-create-table)
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## SHOW DICTIONARIES
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Displays a list of [Dictionaries](../../sql-reference/dictionaries/external-dictionaries/external-dicts.md).
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``` sql
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SHOW DICTIONARIES [FROM <db>] [LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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If the `FROM` clause is not specified, the query returns the list of dictionaries from the current database.
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You can get the same results as the `SHOW DICTIONARIES` query in the following way:
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``` sql
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SELECT name FROM system.dictionaries WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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**Example**
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The following query selects the first two rows from the list of tables in the `system` database, whose names contain `reg`.
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``` sql
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SHOW DICTIONARIES FROM db LIKE '%reg%' LIMIT 2
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```
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``` text
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┌─name─────────┐
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│ regions │
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│ region_names │
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└──────────────┘
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```
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## SHOW GRANTS
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Shows privileges for a user.
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### Syntax
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``` sql
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SHOW GRANTS [FOR user1 [, user2 ...]]
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```
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If user is not specified, the query returns privileges for the current user.
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## SHOW CREATE USER
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Shows parameters that were used at a [user creation](../../sql-reference/statements/create/user.md).
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`SHOW CREATE USER` does not output user passwords.
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### Syntax
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``` sql
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SHOW CREATE USER [name1 [, name2 ...] | CURRENT_USER]
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```
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## SHOW CREATE ROLE
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Shows parameters that were used at a [role creation](../../sql-reference/statements/create/role.md).
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### Syntax
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``` sql
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SHOW CREATE ROLE name1 [, name2 ...]
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```
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## SHOW CREATE ROW POLICY
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Shows parameters that were used at a [row policy creation](../../sql-reference/statements/create/row-policy.md).
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### Syntax
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``` sql
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SHOW CREATE [ROW] POLICY name ON [database1.]table1 [, [database2.]table2 ...]
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```
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## SHOW CREATE QUOTA
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Shows parameters that were used at a [quota creation](../../sql-reference/statements/create/quota.md).
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### Syntax
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``` sql
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SHOW CREATE QUOTA [name1 [, name2 ...] | CURRENT]
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```
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## SHOW CREATE SETTINGS PROFILE
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Shows parameters that were used at a [settings profile creation](../../sql-reference/statements/create/settings-profile.md).
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### Syntax
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``` sql
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SHOW CREATE [SETTINGS] PROFILE name1 [, name2 ...]
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```
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## SHOW USERS
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Returns a list of [user account](../../operations/access-rights.md#user-account-management) names. To view user accounts parameters, see the system table [system.users](../../operations/system-tables/users.md#system_tables-users).
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### Syntax
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``` sql
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SHOW USERS
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```
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## SHOW ROLES
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Returns a list of [roles](../../operations/access-rights.md#role-management). To view another parameters, see system tables [system.roles](../../operations/system-tables/roles.md#system_tables-roles) and [system.role_grants](../../operations/system-tables/role-grants.md#system_tables-role_grants).
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### Syntax
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``` sql
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SHOW [CURRENT|ENABLED] ROLES
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```
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## SHOW PROFILES
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Returns a list of [setting profiles](../../operations/access-rights.md#settings-profiles-management). To view user accounts parameters, see the system table [settings_profiles](../../operations/system-tables/settings_profiles.md#system_tables-settings_profiles).
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### Syntax
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``` sql
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SHOW [SETTINGS] PROFILES
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```
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## SHOW POLICIES
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Returns a list of [row policies](../../operations/access-rights.md#row-policy-management) for the specified table. To view user accounts parameters, see the system table [system.row_policies](../../operations/system-tables/row_policies.md#system_tables-row_policies).
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### Syntax
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``` sql
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SHOW [ROW] POLICIES [ON [db.]table]
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```
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## SHOW QUOTAS
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Returns a list of [quotas](../../operations/access-rights.md#quotas-management). To view quotas parameters, see the system table [system.quotas](../../operations/system-tables/quotas.md#system_tables-quotas).
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### Syntax
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``` sql
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SHOW QUOTAS
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```
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## SHOW QUOTA
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Returns a [quota](../../operations/quotas.md) consumption for all users or for current user. To view another parameters, see system tables [system.quotas_usage](../../operations/system-tables/quotas_usage.md#system_tables-quotas_usage) and [system.quota_usage](../../operations/system-tables/quota_usage.md#system_tables-quota_usage).
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### Syntax
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``` sql
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SHOW [CURRENT] QUOTA
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```
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## SHOW ACCESS
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Shows all [users](../../operations/access-rights.md#user-account-management), [roles](../../operations/access-rights.md#role-management), [profiles](../../operations/access-rights.md#settings-profiles-management), etc. and all their [grants](../../sql-reference/statements/grant.md#grant-privileges).
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### Syntax
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``` sql
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SHOW ACCESS
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```
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## SHOW CLUSTER(s)
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Returns a list of clusters. All available clusters are listed in the [system.clusters](../../operations/system-tables/clusters.md) table.
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:::note
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`SHOW CLUSTER name` query displays the contents of system.clusters table for this cluster.
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:::
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### Syntax
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``` sql
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SHOW CLUSTER '<name>'
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SHOW CLUSTERS [LIKE|NOT LIKE '<pattern>'] [LIMIT <N>]
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```
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### Examples
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Query:
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``` sql
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SHOW CLUSTERS;
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```
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Result:
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```text
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┌─cluster──────────────────────────────────────┐
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│ test_cluster_two_shards │
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│ test_cluster_two_shards_internal_replication │
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│ test_cluster_two_shards_localhost │
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│ test_shard_localhost │
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│ test_shard_localhost_secure │
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│ test_unavailable_shard │
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└──────────────────────────────────────────────┘
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```
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Query:
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``` sql
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SHOW CLUSTERS LIKE 'test%' LIMIT 1;
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```
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Result:
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```text
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┌─cluster─────────────────┐
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│ test_cluster_two_shards │
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└─────────────────────────┘
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```
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Query:
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``` sql
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SHOW CLUSTER 'test_shard_localhost' FORMAT Vertical;
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```
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Result:
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```text
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Row 1:
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──────
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cluster: test_shard_localhost
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shard_num: 1
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shard_weight: 1
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replica_num: 1
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host_name: localhost
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host_address: 127.0.0.1
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port: 9000
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is_local: 1
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user: default
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default_database:
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errors_count: 0
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estimated_recovery_time: 0
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```
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## SHOW SETTINGS
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Returns a list of system settings and their values. Selects data from the [system.settings](../../operations/system-tables/settings.md) table.
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**Syntax**
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```sql
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SHOW [CHANGED] SETTINGS LIKE|ILIKE <name>
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```
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**Clauses**
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`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.
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When the `CHANGED` clause is used, the query returns only settings changed from their default values.
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**Examples**
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Query with the `LIKE` clause:
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```sql
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SHOW SETTINGS LIKE 'send_timeout';
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```
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Result:
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```text
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┌─name─────────┬─type────┬─value─┐
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│ send_timeout │ Seconds │ 300 │
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└──────────────┴─────────┴───────┘
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```
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Query with the `ILIKE` clause:
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```sql
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SHOW SETTINGS ILIKE '%CONNECT_timeout%'
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```
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Result:
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```text
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┌─name────────────────────────────────────┬─type─────────┬─value─┐
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│ connect_timeout │ Seconds │ 10 │
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│ connect_timeout_with_failover_ms │ Milliseconds │ 50 │
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│ connect_timeout_with_failover_secure_ms │ Milliseconds │ 100 │
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└─────────────────────────────────────────┴──────────────┴───────┘
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```
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Query with the `CHANGED` clause:
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```sql
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SHOW CHANGED SETTINGS ILIKE '%MEMORY%'
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```
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Result:
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```text
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┌─name─────────────┬─type───┬─value───────┐
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│ max_memory_usage │ UInt64 │ 10000000000 │
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└──────────────────┴────────┴─────────────┘
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```
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## SHOW FILESYSTEM CACHES
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```sql
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SHOW FILESYSTEM CACHES
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```
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Result:
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``` text
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┌─Caches────┐
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│ s3_cache │
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└───────────┘
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```
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**See Also**
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- [system.settings](../../operations/system-tables/settings.md) table
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[Original article](https://clickhouse.com/docs/en/sql-reference/statements/show/) <!--hide-->
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