Jeff Amiel writes:
>> At the moment I think the only way to work around this is
>> to denormalize
>> your schema a bit.
> And I feared as much.
> It's biting me in other areas as well...this unusual distribution of
> data...certain types of customers have completely different data patterns
> t
--- On Fri, 12/2/11, Tom Lane wrote:
> The only real fix for that will require cross-column
> statistics, which
> we don't have yet --- without such, there's no way for the
> planner to
> know that distributors have an atypical number of child
> customers.
The only caveat that I can think of
--- On Fri, 12/2/11, Tom Lane wrote:
> The only real fix for that will require cross-column
> statistics, which
> we don't have yet --- without such, there's no way for the
> planner to
> know that distributors have an atypical number of child
> customers.
>
I suspected as such.
> At the mo
--- On Fri, 12/2/11, David Johnston wrote:
>
>
> Can you wrap the query into an SQL or PL/pgSQL function so
> that, at least,
> then planner will not be able to see the embedded plan info
> in the outer
> queries? You use-case may allow
-Original Message-
From: Jeff Amiel [mailto:becauseimj...@yahoo.com]
Sent: Friday, December 02, 2011 5:07 PM
To: pgsql-general@postgresql.org; David Johnston
Subject: RE: [GENERAL] Oddball data distribution giving me planner headaches
--- On Fri, 12/2/11, David Johnston wrote:
> F
Jeff Amiel writes:
> Oddball data distribution giving me headaches.
> [ 'distributor' customers have many more child customers than average ]
> Does this oddball data distribution doom me to poor planning forever?
The only real fix for that will require cross-column statistics, which
we don't hav
--- On Fri, 12/2/11, David Johnston wrote:
> From: David Johnston
> -
> My, possibly naïve, observation:
>
> So aside from the fact the estimates seem to be off the
> planner has still
> chosen the most effective plan? In that situati
-Original Message-
From: Jeff Amiel [mailto:becauseimj...@yahoo.com]
Sent: Friday, December 02, 2011 4:15 PM
To: pgsql-general@postgresql.org; David Johnston
Subject: RE: [GENERAL] Oddball data distribution giving me planner headaches
--- On Fri, 12/2/11, David Johnston wrote:
> W
--- On Fri, 12/2/11, David Johnston wrote:
> What happens if you disable, say, nested loops and/or index
> scans?
planner selects different join/indexing techniques (query is slower) but row
estimates (bad) remain identical.
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.o
-Original Message-
From: Jeff Amiel [mailto:becauseimj...@yahoo.com]
Sent: Friday, December 02, 2011 3:52 PM
To: pgsql-general@postgresql.org; David Johnston
Subject: RE: [GENERAL] Oddball data distribution giving me planner headaches
--- On Fri, 12/2/11, David Johnston wrote:
> F
--- On Fri, 12/2/11, David Johnston wrote:
> From: David Johnston
> What kind of plan does the following give?
>
> EXPLAIN ANALYZE
> SELECT *
> FROM customer_rel p
> JOIN customer c ON (p.parent_customer = c.customer_id)
> WHERE c.customer_type = 'DISTRIBUTOR'
Nearly identical output
"Nested
-Original Message-
From: pgsql-general-ow...@postgresql.org
[mailto:pgsql-general-ow...@postgresql.org] On Behalf Of Jeff Amiel
Sent: Friday, December 02, 2011 3:20 PM
To: pgsql-general@postgresql.org
Subject: [GENERAL] Oddball data distribution giving me planner headaches
explain
Oddball data distribution giving me headaches.
We have a distinct 'customer' table with customer_id, type and name/demographic
information.
Assume some 1 million rows in the customer table.
We then have a customer 'relationship' table which simply contains 2
columns…designating parent and chil
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