Time-Series Extensions
This section lists SQL extensions supported by Feldera for computing over time-series data. A time series is a sequence of events, such as IoT sensor readings or financial transactions, where each event is associated with one or more timestamps.
Refer to the guide on time series analysis with Feldera for a detailed description of these constructs and their usage.
LATENESS expressions
Lateness is a constant bound associated with a timestamp column in a table or view, such that updates to the table are not allowed to arrive more than lateness time units out of order.
See the Time Series Analysis Guide for details.
WATERMARK expressions
The WATERMARK feature is still experimental, and it may be removed
or substantially modified in the future.
WATERMARK is an annotation on a column of a table that delays the processing
of the input rows by a constant amount of time.
See the Time Series Analysis Guide for details.
append_only tables
The append_only annotation on a table instructs Feldera that the table will
only receive INSERT updates.
See the Time Series Analysis Guide for details.
emit_final views
The emit_final feature is still experimental, and it may be removed
or substantially modified in the future.
The emit_final annotation on a view instructs Feldera to only output its final rows,
i.e., rows that are guaranteed to never get deleted or updated.
See the Time Series Analysis Guide for details.