druid/docs/development/extensions-core/datasketches-extension.md
Gian Merlino d007477742
Docusaurus build framework + ingestion doc refresh. (#8311)
* Docusaurus build framework + ingestion doc refresh.

* stick to npm instead of yarn

* fix typos

* restore some _bin

* Adjustments.

* detect and fix redirect anchors

* update anchor lint

* Web-console: remove specific column filters (#8343)

* add clear filter

* update tool kit

* remove usless check

* auto run

* add %

* Fix resource leak (#8337)

* Fix resource leak

* Patch comments

* Enable Spotbugs NP_NONNULL_RETURN_VIOLATION (#8234)

* Fixes from PR review.

* Fix more anchors.

* Preamble nix.

* Fix more anchors, headers

* clean up placeholder page

* add to website lint to travis config

* better broken link checking

* travis fix

* Fixed more broken links

* better redirects

* unfancy catch

* fix LGTM error

* link fixes

* fix md issues

* Addl fixes
2019-08-20 21:48:59 -07:00

2.1 KiB

id title
datasketches-extension DataSketches extension

Apache Druid (incubating) aggregators based on datasketches library. Sketches are data structures implementing approximate streaming mergeable algorithms. Sketches can be ingested from the outside of Druid or built from raw data at ingestion time. Sketches can be stored in Druid segments as additive metrics.

To use the datasketches aggregators, make sure you include the extension in your config file:

druid.extensions.loadList=["druid-datasketches"]

The following modules are available:

  • Theta sketch - approximate distinct counting with set operations (union, intersection and set difference).
  • Tuple sketch - extension of Theta sketch to support values associated with distinct keys (arrays of numeric values in this specialized implementation).
  • Quantiles sketch - approximate distribution of comparable values to obtain ranks, quantiles and histograms. This is a specialized implementation for numeric values.
  • HLL sketch - approximate distinct counting using very compact HLL sketch.