What are OLAP functions? There are some difference between Aggregate functions and OLAP functions.
When OLAP functions are combined with standard SQL within the data warehouse,
they provide the ability to analyze large amounts of historical, business
transactions from the past through the present. Plus, they provide the ability
to project possible future values.
The OLAP functions are the cousins of the aggregate functions,
but are very different in their use.
Like traditional aggregates, OLAP functions
operate on groups of rows and permit qualification and filtering of the group
result.
Unlike aggregates, OLAP functions also return the individual row detail
data and not just the final aggregated value.
Command

Description


CSUM

Cumulative sum of a referenced value, for a range or
dimension.

MSUM

Computation of a moving sum of a referenced value, based on a
specified window.

MAVG

Computation of a moving average of a referenced value, based on
a specified window.

MDIFF

Computation of a moving difference between two referenced data
values, based on a specified window.

MLINREG

Computation of a moving linear regression between two
referenced data values, based on a specified window.

RANK

Ranking based on high order or low order of a referenced data
value, based on a specified value.

QUANTILE

Categorize a referenced data value, based on a number of
partitions.

SAMPLE

Returns only a sample of all rows that would otherwise be
returned.

RANDOM

Generates a random number within a specified range.

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