enum class JoinType
DataFrame joining
Nice Intro http://www.cburch.com/cs/340/reading/join/index.html https://de.wikipedia.org/wiki/Joinalgorithmen http://codeaffectionate.blogspot.de/2012/09/fun-with-cartesian-products-cartesian.html https://www.informatik.hu-berlin.de/de/forschung/gebiete/wbi/teaching/archive/sose05/dbs2/slides/09_joins.pdf
LEFT |
|
RIGHT |
|
INNER |
|
OUTER |