4f769b903b
## What changes were proposed in this pull request? Join processing in the parser relies on the fact that the grammar produces a right nested trees, for instance the parse tree for `select * from a join b join c` is expected to produce a tree similar to `JOIN(a, JOIN(b, c))`. However there are cases in which this (invariant) is violated, like: ```sql SELECT COUNT(1) FROM test T1 CROSS JOIN test T2 JOIN test T3 ON T3.col = T1.col JOIN test T4 ON T4.col = T1.col ``` In this case the parser returns a tree in which Joins are located on both the left and the right sides of the parent join node. This PR introduces a different grammar rule which does not make this assumption. The new rule takes a relation and searches for zero or more joined relations. As a bonus processing is much easier. ## How was this patch tested? Existing tests and I have added a regression test to the plan parser suite. Author: Herman van Hovell <hvanhovell@databricks.com> Closes #14867 from hvanhovell/SPARK-17296. |
||
---|---|---|
.. | ||
src | ||
pom.xml |