>>>>> "Andreas" == Andreas Karlsson <andr...@proxel.se> writes:
> On 10/03/2018 05:57 PM, David Fetter wrote: >> Is there any meaningful distinction between "inlining," by which I >> mean converting to a subquery, and predicate pushdown, which >> would happen at least for a first cut, at the rewrite stage? Yes. Andreas> Sorry, but I do not think I understand your question. The Andreas> ability to push down predicates is just one of the potential Andreas> benefits from inlining. Consider the difference between (in the absence of CTE inlining): -- inline subquery with no optimization barrier (qual may be pushed down) select * from (select x from y) s where x=1; -- inline subquery with optimization barrier (qual not pushed down) select * from (select x from y offset 0) s where x=1; -- CTE with materialization with s as (select x from y) select * from s where x=1; -- Andrew (irc:RhodiumToad)
