* Add IPv4 SQL functions
New SQL functions for filtering IPv4 addresses:
- IPV4_MATCH: Check if IP address belongs to a subnet
- IPV4_PARSE: Convert string IP address to integer
- IPV4_STRINGIFY: Convert integer IP address to string
These are the SQL analogs of the druid expressions with the same name.
Filtering is more efficient when operating on IP addresses as integers
instead of strings.
* Refactor operator conversions into named constants
The behavior is now that filters on "null" will match rows with no
values. The behavior in the past was inconsistent; sometimes these
filters would match and sometimes they wouldn't.
Adds tests for this behavior to SelectorFilterTest and
BoundFilterTest, for query-level filters and filtered aggregates.
Fixes#2750.
- Add central doc for multi-value dimensions, with some content from other docs.
- Link to multi-value dimension doc from topN and groupBy docs.
- Fixes a broken link from dimensionspecs.md, which was presciently already
linking to this nonexistent doc.
- Resolve inconsistent naming in docs & code (sometimes "multi-valued", sometimes
"multi-value") in favor of "multi-value".
Chi Cao Minh
Clint Wylie
Jonathan Wei
David Lim
Vadim Ogievetsky
Erik Dubbelboer
Kirill Kozlov
Gian Merlino