add unit tests for IndexMergerV9 and fix some bugs
add more unit tests and fix bugs
handle null values and add more tests
minor changes & use LoggingProgressIndicator in IndexGeneratorReducer
make some static class public from IndexMerger
minor changes and add some comments
changes for comments
Version 2 - Throws an exception if an outer query references an
aggregator that doesn't exist in the inner query, and then uses the
inner query aggregator names to form the columns for the intermediate
incremental index.
Also deleted all the getRequiredColumns() methods which are no longer
being used.
We do something wacky by adding an aggregator factory for the post
aggregators when building the intermediate incremental index, otherwise
queries on post aggregate results fail because the data isn't in the
incremental index.
Closes#1419
renamed all [Max/Min]*.java to [DoubleMax/DoubleMin]*.java and created [Max/Min]AggregatorFactory.java which can be removed when we dont need the min/max aggregator type backward compatibility
* add test for same-name groupBy hyperUniques post-agg
* add test for same-name post-agg in groupby with approx histogram
* Fixes https://github.com/druid-io/druid/issues/1045
* Throws an error if post aggs and aggs do not have unique names
* Add more groupBy tests for Having filters
