Re: Performance of a nested loop, whose inner loop uses an index scan.

<p>Hi Matheus:<p>Thanks for your prompt answer. It's for a web application. This part of the application allows to
exportthe answers to a CSV file. So pagination isn't possible here. The user can choose among several filters. The
groupof the courses is one of them. She can combine as many filters as she wants. So the query that I presented in my
previousmessage was one of the "broadest" examples. But it's the one that I'm interested in.<br /><p>Really, <b>I'm
moreinterested in the relative time than in the absolute time.</b> Because I could create the file asynchronously, in
thebackground, so that the user downloaded it at a later time. That's not the problem. My doubt is if 2.8 seconds is
thebest that I can do. Is it an acceptable time?<p>Thank you! ;)<p><br /><div class="moz-cite-prefix">On 19/10/16
13:15,Matheus de Oliveira wrote:<br /></div><blockquote
cite="mid:CAJghg4Lbs-a-_xTmdTWcuQTiZCpv8hTjv2-kWc2_teyNAWiD8w@mail.gmail.com"type="cite"><div dir="ltr"><div
class="gmail_extra"><br/><div class="gmail_quote">On Wed, Oct 19, 2016 at 8:54 AM, negora <span dir="ltr"><<a
href="mailto:public@negora.com"moz-do-not-send="true" target="_blank">public@negora.com</a>></span> wrote:<br
/><blockquoteclass="gmail_quote" style="margin:0 0 0             .8ex;border-left:1px #ccc solid;padding-left:1ex"><div
class="a3saXjCH m157dc958f4b446ce" id=":1ai">     Nested Loop  (cost=245.92..383723.28 rows=7109606 width=38)
(actual<br/> time=1.091..2616.553 rows=8906075 loops=1)</div></blockquote></div><br /></div><div class="gmail_extra">I
wonderabout the use-case for this query, because it returns more than 8M rows, so 2.6 seconds that sounds that much for
somany rows. Is it for an end user application? Isn't there any kind of pagination?<br /></div><div
class="gmail_extra"><brclear="all" /><br /> -- <br /><div class="gmail_signature" data-smartmail="gmail_signature"><div
dir="ltr"><div>Matheusde Oliveira<br /><br /><br /></div></div></div></div></div></blockquote><br />