* Add an option to SearchQuery to choose a search query execution strategy.
Supported strategies are
1) Index-only query execution
2) Cursor-based scan
3) Auto: choose an efficient strategy for a given query
* Add SearchStrategy and SearchQueryExecutor
* Address comments
* Rename strategies and set UseIndexesStrategy as the default strategy
* Add a cost-based planner for auto strategy
* Add document
* Fix code style
* apply code style
* apply comments
* Add numeric StringComparator
* Only use direct long comparison for numeric ordering in BoundFilter, add time filtering benchmark query
* Address PR comments, add multithreaded BoundDimFilter test
* Add comment on strlen tie handling
* Add timeseries interval filter benchmark
* Adjust docs
* Use jackson for StringComparator, address PR comments
* Add new TopNMetricSpec and SearchSortSpec with tests (WIP)
* More TopNMetricSpec and SearchSortSpec tests
* Fix NewSearchSortSpec serde
* Update docs for new DimensionTopNMetricSpec
* Delete NumericDimensionTopNMetricSpec
* Delete old SearchSortSpec
* Rename NewSearchSortSpec to SearchSortSpec
* Add TopN numeric comparator benchmark, address PR comments
* Refactor OrderByColumnSpec
* Add null checks to NumericComparator and String->BigDecimal conversion function
* Add more OrderByColumnSpec serde tests
* support alphanumeric sort in search query
* address a comment about handling equals() and hashCode()
* address comments
* add Ut for string comparators
* address a comment about space indentations.
David Lim
Jihoon Son
Jonathan Wei
jaehong choi
navis.ryu
Slim Bouguerra
Himanshu Gupta