trailing_window_frame

Builds the OVER(…) frame shared by trailing_median and trailing_observation_count.

Builds the OVER(…) frame shared by trailing_median and trailing_observation_count. The frame ALWAYS ends at 1 PRECEDING. That is the whole point: it is what makes the window backward-only, so a row is never scored against a value it could not have seen. Do not add a variant that ends at CURRENT ROW — a baseline that includes the lap it scores is a different statistic, and the two must not share a name.

Signature

{{ trailing_window_frame(partition_by, order_by, lookback=none, frame='rows') }}

Arguments

Argument	Description
partition_by	list of column names, or a raw string, or none for an UNPARTITIONED window (one global series — e.g. the pooled shrinkage prior in int_sc_hazard_history, which is a rate across all circuits and so has no entity to partition by). none is not the same as omitting the
argument	it is a deliberate “the whole table is one series”.
order_by	list of column names, or a raw string (the time axis)
lookback	integer N for N PRECEDING, or none for UNBOUNDED PRECEDING
frame	’rows’ or ‘range’. ROWS counts rows; RANGE counts values of the ORDER BY column, which is what a FIELD statistic across several entities at the same time index needs (see 02g), and what a SEASON-lagged statistic needs when a season may hold many rows (02d).