OPAL Window Functions

Function	Description
any	Return any value of one column across a group
any_not_null	Return any non-null value of one column across a…
avg	Calculate the arithmetic average of the input…
count	Count the number of non-null items in the group.
count_distinct	Estimate the approximate number of distinct values…
count_distinct_exact	Count the exact number of distinct values in the…
dense_rank	Returns the dense rank within an ordered group of…
deriv	Calculate the average per-second derivative of the…
first	Return the first value of one column across an…
first_not_null	Return the first non-null value of one column across…
lag	Return the lag of one column across an ordered…
last	Return the last value of one column across an…
last_not_null	Return the last non-null value of one column across…
lead	Return the lead of one column across an ordered…
max	Compute the maximum of one column across a group…
median	Return the fast approximate median value of one…
median_exact	Return the exact median value of one column.
min	Compute the minimum of one column across a group…
object_agg	Returns one OBJECT per group. For each (key, value)…
percentile	Returns an approximated value for the specified…
percentile_cont	Assuming a continuous distribution, it returns the…
percentile_disc	Assuming a discrete distribution, it returns the…
rank	Returns the rank within an ordered group of values….
rate	Calculate the average per-second rate of the…
row_number	Return the window index of the row within its…
stddev	Calculate the standard deviation across the group.
sum	Calculate the sum of the argument across the group,…