Introduce Histogram grouping function for bucketing/grouping data based
on a given range. Both date and numeric histograms are supported using
the appropriate range declaration (numbers vs intervals).
SELECT HISTOGRAM(number, 50) AS h FROM index GROUP BY h
SELECT HISTOGRAM(date, INTERVAL 1 YEAR) AS h FROM index GROUP BY h
In addition add multiply operator for Intervals
Add docs for intervals and histogram
Fix#36509
Split function section into multiple chapters
Add String functions
Add (small) section on Conversion/Cast functions
Add missing aggregation functions
Enable documentation testing (was disabled by accident). While at it,
fix failing tests
Improve spec tests to allow multi-line queries (useful for docs)
Add ability to ignore a spec test (name should end with -Ignore)