Re: Indirect indexes - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Indirect indexes
Date
Msg-id 20161020152440.GB18972@momjian.us
Whole thread Raw
In response to Re: Indirect indexes  (Petr Jelinek <petr@2ndquadrant.com>)
Responses Re: Indirect indexes  (Petr Jelinek <petr@2ndquadrant.com>)
Re: Indirect indexes  (Pantelis Theodosiou <ypercube@gmail.com>)
List pgsql-hackers
On Thu, Oct 20, 2016 at 05:14:51PM +0200, Petr Jelinek wrote:
> > Also, it seems indirect indexes would be useful for indexing columns
> > that are not updated frequently on tables that are updated frequently,
> > and whose primary key is not updated frequently.  That's quite a logic
> > problem for users to understand.
> > 
> 
> Which covers like 99.9% of problematic cases I see on daily basis.
> 
> And by that logic we should not have indexes at all, they are not
> automatically created and user needs to think about if they need them or
> not.

Do you have to resort to extreme statements to make your point?  The use
of indexes is clear to most users, while the use of indirect indexes
would not be, as I stated earlier.

> Also helping user who does not have performance problem by 1% is very
> different from helping user who has performance problem by 50% even if
> she needs to think about the solution a bit.
> 
> WARM can do WARM update 50% of time, indirect index can do HOT update
> 100% of time (provided the column is not changed), I don't see why we
> could not have both solutions.

We don't know enough about the limits of WARM to say it is limited to
50%.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +



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