How The Statement Timeout Works

How the Statement Timeout Works

When the statement starts execution, or a cursor is opened, the engine starts a special timer.It is stopped when the statement completes execution, or the last record has been fetched by the cursor.

Note	A fetch does not reset this timer.

When the timeout point is reached:

if statement execution is active, it stops at closest possible moment
if statement is not active currently (between fetches, for example), it is marked as cancelled, and the next fetch will break execution and return an error

Note	Statement types excluded from timeouts Statement timeouts are not applicable to some types of statement and will be ignored: All DDL statements All internal queries issued by the engine itself

Setting a Statement Timeout

Note	The timer will not start if the timeout period is set to zero.

A statement timeout can be set:

at database level, by the database administrator, by setting the configuration parameter StatementTimeout in firebird.conf or databases.conf.StatementTimeout is an integer representing the number of seconds after which statement execution will be cancelled automatically by the engine.Zero means no timeout is set.A non-zero setting will affect all statements in all connections.
at connection level, using SET STATEMENT TIMEOUT or the API for setting a statement timeout (setStatementTimeout).A connection-level setting (via SQL or the API) affects all statements for the given connection;units for the timeout period at this level can be specified to any granularity from hours to milliseconds.
at statement level, using the API, in milliseconds