ClickHouse/docs/en/sql-reference/statements/kill.md
Roman Bug 9ec78855cd
DOCSUP-2806: Add meta header in RU (#15801)
* DOCSUP-2806: Add meta intro.

* DOCSUP-2806: Update meta intro.

* DOCSUP-2806: Fix meta.

* DOCSUP-2806: Add quotes for meta headers.

* DOCSUP-2806: Remove quotes from meta headers.

* DOCSUP-2806: Add meta headers.

* DOCSUP-2806: Fix quotes in meta headers.

* DOCSUP-2806: Update meta headers.

* DOCSUP-2806: Fix link to nowhere in EN.

* DOCSUP-2806: Fix link (settings to tune)

* DOCSUP-2806: Fix links.

* DOCSUP-2806:Fix links EN

* DOCSUP-2806: Fix build errors.

* DOCSUP-2806: Fix meta intro.

* DOCSUP-2806: Fix toc_priority in examples datasets TOC.

* DOCSUP-2806: Fix items order in toc.

* DOCSUP-2806: Fix order in toc.

* DOCSUP-2806: Fix toc order.

* DOCSUP-2806: Fix order in toc.

* DOCSUP-2806: Fix toc index in create

* DOCSUP-2806: Fix toc order in create.

Co-authored-by: romanzhukov <romanzhukov@yandex-team.ru>
Co-authored-by: alexey-milovidov <milovidov@yandex-team.ru>
2020-10-26 13:29:30 +03:00

71 lines
2.6 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

---
toc_priority: 46
toc_title: KILL
---
# KILL Statements {#kill-statements}
There are two kinds of kill statements: to kill a query and to kill a mutation
## KILL QUERY {#kill-query-statement}
``` sql
KILL QUERY [ON CLUSTER cluster]
WHERE <where expression to SELECT FROM system.processes query>
[SYNC|ASYNC|TEST]
[FORMAT format]
```
Attempts to forcibly terminate the currently running queries.
The queries to terminate are selected from the system.processes table using the criteria defined in the `WHERE` clause of the `KILL` query.
Examples:
``` sql
-- Forcibly terminates all queries with the specified query_id:
KILL QUERY WHERE query_id='2-857d-4a57-9ee0-327da5d60a90'
-- Synchronously terminates all queries run by 'username':
KILL QUERY WHERE user='username' SYNC
```
Read-only users can only stop their own queries.
By default, the asynchronous version of queries is used (`ASYNC`), which doesnt wait for confirmation that queries have stopped.
The synchronous version (`SYNC`) waits for all queries to stop and displays information about each process as it stops.
The response contains the `kill_status` column, which can take the following values:
1. `finished` The query was terminated successfully.
2. `waiting` Waiting for the query to end after sending it a signal to terminate.
3. The other values explain why the query cant be stopped.
A test query (`TEST`) only checks the users rights and displays a list of queries to stop.
## KILL MUTATION {#kill-mutation}
``` sql
KILL MUTATION [ON CLUSTER cluster]
WHERE <where expression to SELECT FROM system.mutations query>
[TEST]
[FORMAT format]
```
Tries to cancel and remove [mutations](../../sql-reference/statements/alter/index.md#alter-mutations) that are currently executing. Mutations to cancel are selected from the [`system.mutations`](../../operations/system-tables/mutations.md#system_tables-mutations) table using the filter specified by the `WHERE` clause of the `KILL` query.
A test query (`TEST`) only checks the users rights and displays a list of queries to stop.
Examples:
``` sql
-- Cancel and remove all mutations of the single table:
KILL MUTATION WHERE database = 'default' AND table = 'table'
-- Cancel the specific mutation:
KILL MUTATION WHERE database = 'default' AND table = 'table' AND mutation_id = 'mutation_3.txt'
```
The query is useful when a mutation is stuck and cannot finish (e.g. if some function in the mutation query throws an exception when applied to the data contained in the table).
Changes already made by the mutation are not rolled back.