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ana-uvarova 2020-12-10 11:13:09 +03:00
parent ac4e99529b
commit 528dca0f63
2 changed files with 14 additions and 6 deletions

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@ -122,9 +122,9 @@ Example:
ALTER TABLE visits MODIFY COLUMN browser Array(String)
```
## ALTER TABLE MODIFY col_name REMOVE what_to_remove
## MODIFY REMOVE
Removes something from the specific column.
Removes something from a column. For example, ______
Syntax:
@ -146,8 +146,8 @@ Result
## See Also
- More about [ALTER](../../sql-reference/statements/alter/#query_language_queries_alter).
- More about [MODIFY column](../../sql-reference/statements/alter/column/#alter_modify-column).
- [ALTER](../../sql-reference/statements/alter/#query_language_queries_alter).
- [MODIFY column](../../sql-reference/statements/alter/column/#alter_modify-column).
Changing the column type is the only complex action it changes the contents of files with data. For large tables, this may take a long time.

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@ -5,15 +5,17 @@ toc_title: TTL
# Manipulations with Table TTL {#manipulations-with-table-ttl}
## MODIFY TTL {#modify-ttl}
You can change [table TTL](../../../engines/table-engines/mergetree-family/mergetree.md#mergetree-table-ttl) with a request of the following form:
``` sql
ALTER TABLE table_name MODIFY TTL ttl_expression;
```
## ALTER TABLE REMOVE TTL
## REMOVE TTL {remove-ttl}
Removes ttl-property from the specified column.
Removes TTL-property from the specified column.
Syntax:
@ -23,6 +25,12 @@ ALTER TABLE table_name MODIFY column_name REMOVE TTL
**Example**
<!--Попробовать:
посмотреть установленные TTL,
показать состояние таблицы до,
удалить TTL
и показать состояние после.-->
Request
```sql