Spark Developer Scripts
This directory contains scripts useful to developers when packaging, testing, or committing to Spark.
Many of these scripts require Apache credentials to work correctly.
This PR adds an initial implementation of count min sketch, contained in a new module spark-sketch under `common/sketch`. The implementation is based on the [`CountMinSketch` class in stream-lib][1]. As required by the [design doc][2], spark-sketch should have no external dependency. Two classes, `Murmur3_x86_32` and `Platform` are copied to spark-sketch from spark-unsafe for hashing facilities. They'll also be used in the upcoming bloom filter implementation. The following features will be added in future follow-up PRs: - Serialization support - DataFrame API integration [1]: https://github.com/addthis/stream-lib/blob/aac6b4d23a8686b000f80baa447e0922ecac3bcb/src/main/java/com/clearspring/analytics/stream/frequency/CountMinSketch.java [2]: https://issues.apache.org/jira/secure/attachment/12782378/BloomFilterandCount-MinSketchinSpark2.0.pdf Author: Cheng Lian <lian@databricks.com> Closes #10851 from liancheng/count-min-sketch.