CREATE METRONOMEmetronome_identifier
(field_identifier
,interval
);
The METRONOME delivers output tuples periodically based on the system clock. In the same way that a musician's metronome can be used to indicate the exact tempo of a piece of music, you can use a METRONOME to control the timing of downstream operations.
At fixed intervals, a METRONOME will produce a tuple with a single timestamp field
named field_identifier
that will contain
the current time value from the system clock on the computer hosting the StreamBase
application.
A METRONOME begins producing tuples as soon as the application starts.