SET LOCK_TIMEOUT (Transact-SQL)

**APPLIES TO:** ![yes](media/yes.png)SQL Server (starting with 2008) ![yes](media/yes.png)Azure SQL Database ![yes](media/yes.png)Azure SQL Data Warehouse ![yes](media/yes.png)Parallel Data Warehouse

Specifies the number of milliseconds a statement waits for a lock to be released.

Topic link icon Transact-SQL Syntax Conventions

Syntax

SET LOCK_TIMEOUT timeout_period

Arguments

timeout_period
Is the number of milliseconds that will pass before Microsoft Microsoft SQL Server returns a locking error. A value of -1 (default) indicates no time-out period (that is, wait forever).

When a wait for a lock exceeds the time-out value, an error is returned. A value of 0 means to not wait at all and return a message as soon as a lock is encountered.

Remarks

At the beginning of a connection, this setting has a value of -1. After it is changed, the new setting stays in effect for the remainder of the connection.

The setting of SET LOCK_TIMEOUT is set at execute or run time and not at parse time.

The READPAST locking hint provides an alternative to this SET option.

CREATE DATABASE, ALTER DATABASE, and DROP DATABASE statements do not honor the SET LOCK_TIMEOUT setting.

Permissions

Requires membership in the public role.

Examples

A: Set the lock timeout to 1800 milliseconds

The following example sets the lock time-out period to 1800 milliseconds.

SET LOCK_TIMEOUT 1800;  
GO

Examples: [!INCLUDEssSDWfull] and [!INCLUDEssPDW]

B. Set the lock timeout to wait forever for a lock to be released.

The following example sets the lock timeout to wait forever and never expire. This is the default behavior that is already set at the beginning of each connection.

SET LOCK_TIMEOUT -1;

The following example sets the lock time-out period to 1800 milliseconds. In this release, SQL Data Warehouse will parse the statement successfully, but will ignore the value 1800 and continue to use the default behavior.

SET LOCK_TIMEOUT 1800;