Marco Gaido 8dbf56c055 [SPARK-24013][SQL] Remove unneeded compress in ApproximatePercentile ... ## What changes were proposed in this pull request? `ApproximatePercentile` contains a workaround logic to compress the samples since at the beginning `QuantileSummaries` was ignoring the compression threshold. This problem was fixed in SPARK-17439, but the workaround logic was not removed. So we are compressing the samples many more times than needed: this could lead to critical performance degradation. This can create serious performance issues in queries like: ``` select approx_percentile(id, array(0.1)) from range(10000000) ``` ## How was this patch tested? added UT Author: Marco Gaido <marcogaido91@gmail.com> Closes #21133 from mgaido91/SPARK-24013.		2018-05-02 11:58:55 -07:00
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src	[SPARK-24013][SQL] Remove unneeded compress in ApproximatePercentile	2018-05-02 11:58:55 -07:00
pom.xml	[SPARK-19550][BUILD][FOLLOW-UP] Remove MaxPermSize for sql module	2018-01-15 07:49:34 -06:00