Category "union"

union all in SQL (Postgres) mess the order

I have a query which is order by date , there is the query I have simplified it a bit but basically is : select * from (select start_date, to_char(end_date,

Spark hangs on union with zero running task

I have two records of type RDD[T] For example: val a: RDD[Integer] = .... val b: RDD[Integer] = ... when I perform val z = a.union(b) println(z) I find the s

Short-circuit UNION? (only execute 2nd clause if 1st clause has no results)

If I do: SELECT * FROM A WHERE conditions UNION SELECT * FROM B WHERE conditions I get the union of the resultset of query of A and resultset of