Yes... i can't exepct useful help with my poor explanation but your aproach is the right answer!
We were limited with from_collapse_limit. Cost now is: 112 Many many thanks. On Thu, Apr 12, 2018 at 5:30 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > =?UTF-8?Q?Eduard_Catal=C3=A0?= <eduard.cat...@gmail.com> writes: > > Given this statement: > > > SELECT *several_fields* FROM A, B, C WHERE *conditions* > > A, B are tables with several LEFT JOINS but they act as one subquery. > > You really can't expect useful help if you are going to pose questions > that abstract. You have removed details that count, and made assumptions > that don't necessarily hold (e.g., what does "act as one subquery" mean?) > > Probably the most likely bet, on this limited information, is that there > are enough base tables hidden inside your query that you're running into > join_collapse_limit and/or from_collapse_limit, resulting in the planner > failing to investigate the best available plan in one case. Raising those > limits would help, if so. But it could easily be something else. > > There's some suggestions here about how to ask useful questions: > > https://wiki.postgresql.org/wiki/Slow_Query_Questions > > regards, tom lane >
