Re: [PERFORM] OLAP/reporting queries fall into nested loops over seq scans or other horrible planner choices

2017-11-02 Thread Laurenz Albe
Gunther wrote: > But there > is one thing that keeps bothering me both with Oracle and PgSQL. And > that is the preference for Nested Loops. [...] > But the issue is bulk searches, reports, and any analytic queries > scenarios. In those queries Nested Loops are almost always a bad choice, > e

Re: [PERFORM] OLAP/reporting queries fall into nested loops over seq scans or other horrible planner choices

2017-11-02 Thread Gunther
Thanks for your support Laurent. I have an idea on one thing you said: Just adding to your voice. I recently experienced the same issue with a complex multi-table view, including pivots, and was surprised to see all the nested loops everywhere and here is the clue for me: in spite of indice

Re: [PERFORM] OLAP/reporting queries fall into nested loops over seq scans or other horrible planner choices

2017-11-02 Thread Gunther
Thanks you for your thoughtful reply, Laurenz (funny that the people interested in this topic are named Laurent and Laurenz :) PostgreSQL doesn't have a way to tell if a query is an OLAP query running against a star schema or a regular OLTP query, it will treat both in the same fashion. right,

[PERFORM] Re: OLAP/reporting queries fall into nested loops over seq scans or other horrible planner choices

2017-11-02 Thread legrand legrand
Hello, may I suggest you to look at https://github.com/ossc-db/pg_hint_plan that mimics Oracle hints syntax Regards PAscal -- Sent from: http://www.postgresql-archive.org/PostgreSQL-performance-f2050081.html -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To m