* Add sample versions of standard deviation and variance functions (#59093)
* Add STDDEV_SAMP, VAR_SAMP
This commit adds the sampling variations of the standard deviation and
variance agg functions.
(cherry picked from commit 8b29817b49e386215f29cb5b3356d0183fd5d9de)
* Fix: workaround for lack of Map#of() in Java8
Replace Map#of() with a HashMap static init.
Implement the use of scalar functions inside aggregate functions.
This allows for complex expressions inside aggregations, with or without
GROUBY as well as with or without a HAVING clause. e.g.:
```
SELECT MAX(CASE WHEN a IS NULL then -1 ELSE abs(a * 10) + 1 END) AS max, b
FROM test
GROUP BY b
HAVING MAX(CASE WHEN a IS NULL then -1 ELSE abs(a * 10) + 1 END) > 5
```
Scalar functions are still not allowed for `KURTOSIS` and `SKEWNESS` as
this is currently not implemented on the ElasticSearch side.
Fixes: #29980Fixes: #36865Fixes: #37271
(cherry picked from commit 506d1beea7abb2b45de793bba2e349090a78f2f9)
* Fix "Description"s for various sections in the functions pages.
* Added a TIP for searching using a routing key.
* Other small polishings
(cherry picked from commit 9fad0b1ac4409a42c435ed040f41cbaea18930a3)
* Document MATCH and QUERY function predicates.
* Polish the functions pages and add a list of functions to the main Functions & Operators page.
(cherry picked from commit 4cec0ae1b962ec7ea011a290aec72740386eb808)
To avoid having to specify each spec by hand (which can miss specs to be
added), the test infrastructure now performs classpath discovery so that
each spec added, is automatically considered.
Relates #40358
(cherry picked from commit d0f60b4425c731509aa8ca765d55f563f866ef90)
FIRST and LAST can be used with one argument and work similarly to MIN
and MAX but they are implemented using a Top Hits aggregation and
therefore can also operate on keyword fields. When a second argument is
provided then they return the first/last value of the first arg when its
values are ordered ascending/descending (respectively) by the values of
the second argument. Currently because of the usage of a Top Hits
aggregation FIRST and LAST cannot be used in the HAVING clause of a
GROUP BY query to filter on the results of the aggregation.
Closes: #35639
* provide overriden `hashCode` and toString methods to account for `DISTINCT`
* change the analyzer for scenarios where `COUNT <field_name>` and `COUNT DISTINCT` have different paths
* defined a new `filter` aggregation encapsulating an `exists` query to filter out null or missing values
Enhance error message for the case that the 2nd argument of PERCENTILE
and PERCENTILE_RANK is not a foldable, as it doesn't make sense to have
a dynamic value coming from a field.
Fixes: #36903
* Added Limitations page
* Made the aggregations page follow the common template for functions
* Modified all tables to have the first row's cells content centered
* Polishing in other various sections
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)
Bogdan Pintea
jmceniery
Marios Trivyzas
Andrei Stefan
James Rodewig
Costin Leau
Costin Leau