bb ddd writes:
> Thanks, Adrian, but i was looking for something that goes into more depth.
Use the source, Luke.
git clone git://git.postgresql.org/git/postgresql.git
Likely places to look for this purpose include
src/backend/optimizer/README
src/backend/optimizer/path/costsize.c
src/backend/
On 5/11/19 2:33 AM, bb ddd wrote:
Thanks, Adrian, but i was looking for something that goes into more depth.
For example there is one case described there where we have a Nested Loop with
rows=33, and its 2 child nodes have each rows=10.
But first of all this is a very exotic join condition (t1
am just guessing.
> Оригинално писмо
>От: Adrian Klaver adrian.kla...@aklaver.com
>Относно: Re: Question about Expected rows value in EXPLAIN output for Nested
Loop node
>До: bb ddd
>Изпратено на: 10.05.2019 19:02
> On 5/10/19 8:56 AM, bb ddd wrote:
> >
On 5/10/19 8:56 AM, bb ddd wrote:
Thanks for the reply. Here it is: https://explain.depesz.com/s/LQCS
My main trouble is not with this exact case, but i am looking for a general
description of the algorithm how those numbers are calculated. In the meanwhile i
also constructed a couple of artif
contexts (like when loops=1 vs
loops>1) maybe what statistics they use, how they depend on the numbers of
their child nodes etc.
> Оригинално писмо
>От: Adrian Klaver adrian.kla...@aklaver.com
>Относно: Re: Question about Expected rows value in EXPLAIN outpu
On 5/10/19 5:32 AM, bb ddd wrote:
Not sure why some of the new lines disappeared in the original message.
here is the part that got most corrupted with some more new lines lets
hope it looks more readable now
1) I have 2 Index Scans inside a Nested Loop
2) Nested Loop's expected rows=1268
Not sure why some of the new lines disappeared in the original message.
here is the part that got most corrupted with some more new lines lets
hope it looks more readable now
1) I have 2 Index Scans inside a Nested Loop
2) Nested Loop's expected rows=1268
3.1) First Index Scan's expected
