Re:Recursive SQL Queries with PostgreSQL
by anarazel on Tuesday March 17, 2020 @01:38PM
(#22607617)
There has to be more to the situation than the aove. Unless you configured join_collapse_limit to be way lower than the default, the JOIN query just gets transformed into the former.
Any chance you either had a lot more tables joined together, or you were seeing caching effects?
> Conversely, projecting off unnecessary columns used to result in a big speedup.
That also just gets inlined, unless you have more than from_collapse_limit items in the from list. And we push down the list of columns we actually need, so there's nothing this would improve anyway.
Any chance you either had a lot more tables joined together, or you were seeing caching effects?
> Conversely, projecting off unnecessary columns used to result in a big speedup.
That also just gets inlined, unless you have more than from_collapse_limit items in the from list. And we push down the list of columns we actually need, so there's nothing this would improve anyway.