T-Digest functions#
Data structures#
A T-digest is a data sketch which stores approximate percentile
information.  The Trino type for this data structure is called tdigest.
T-digests can be merged, and for storage and retrieval they can be cast
to and from VARBINARY.
Functions#
- merge(tdigest) tdigest
- Aggregates all inputs into a single - tdigest.
- value_at_quantile(tdigest, quantile) double
- Returns the approximate percentile value from the T-digest, given the number - quantilebetween 0 and 1.
- values_at_quantiles(tdigest, quantiles)
- Returns the approximate percentile values as an array, given the input T-digest and an array of values between 0 and 1, which represent the quantiles to return. 
- tdigest_agg(x) tdigest#
- Composes all input values of - xinto a- tdigest.- xcan be of any numeric type.
- tdigest_agg(x, w) tdigest
- Composes all input values of - xinto a- tdigestusing the per-item weight- w.- wmust be greater or equal than 1.- xand- wcan be of any numeric type.