# WAIT and NOWAIT

Extended syntax so that it is possible to set [innodb\_lock\_wait\_timeout](https://mariadb.com/docs/server/server-usage/storage-engines/innodb/innodb-system-variables#innodb_lock_wait_timeout) and [lock\_wait\_timeout](https://mariadb.com/docs/server/server-management/variables-and-modes/server-system-variables#lock_wait_timeout) for the following statements:

## Syntax

```sql
ALTER TABLE tbl_name [WAIT n|NOWAIT] ...
CREATE ... INDEX ON tbl_name (index_col_name, ...) [WAIT n|NOWAIT] ...
DROP INDEX ... [WAIT n|NOWAIT]
DROP TABLE tbl_name [WAIT n|NOWAIT] ...
LOCK TABLE ... [WAIT n|NOWAIT]
OPTIMIZE TABLE tbl_name [WAIT n|NOWAIT]
RENAME TABLE tbl_name [WAIT n|NOWAIT] ...
SELECT ... FOR UPDATE [WAIT n|NOWAIT]
SELECT ... LOCK IN SHARE MODE [WAIT n|NOWAIT]
TRUNCATE TABLE tbl_name [WAIT n|NOWAIT]
```

## Description

The lock wait timeout can be explicitly set in the statement by using either `WAIT n` (to set the wait in seconds) or `NOWAIT`, in which case the statement will immediately fail if the lock cannot be obtained. `WAIT 0` is equivalent to `NOWAIT`.

## See Also

* [Query Limits and Timeouts](https://mariadb.com/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/query-limits-and-timeouts)
* [ALTER TABLE](https://mariadb.com/docs/server/reference/sql-statements/data-definition/alter/alter-table)
* [CREATE INDEX](https://mariadb.com/docs/server/reference/sql-statements/data-definition/create/create-index)
* [DROP INDEX](https://mariadb.com/docs/server/reference/sql-statements/data-definition/drop/drop-index)
* [DROP TABLE](https://mariadb.com/docs/server/server-usage/tables/drop-table)
* [LOCK TABLES and UNLOCK TABLES](https://mariadb.com/docs/server/reference/sql-statements/transactions/lock-tables)
* [OPTIMIZE TABLE](https://mariadb.com/docs/server/ha-and-performance/optimization-and-tuning/optimizing-tables/optimize-table)
* [RENAME TABLE](https://mariadb.com/docs/server/reference/sql-statements/data-definition/rename-table)
* [SELECT](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/selecting-data/select)
* [TRUNCATE TABLE](https://mariadb.com/docs/server/reference/sql-statements/table-statements/truncate-table)

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