On Thu, 2006-03-16 at 14:45 -0500, Tom Lane wrote:
> Simon Riggs <[EMAIL PROTECTED]> writes:
> > [BTW how do you add new indexes to system tables? I want to add one to
> > pg_inherits but not sure where to look.]
>
> src/include/catalog/indexing.h
>
> Offhand I think adding a new entry is all you
Simon Riggs <[EMAIL PROTECTED]> writes:
> I was thinking that we would fill out the OpExpr with different
> opclasses for each plan, so each one sees a different story. (I was
> thinking there was a clauselist for each plan; if not, there could be.)
This is backwards: there isn't a plan yet. If t
On Thu, 2006-03-16 at 15:41 -0400, Alvaro Herrera wrote:
> Simon Riggs wrote:
>
> > [BTW how do you add new indexes to system tables? I want to add one to
> > pg_inherits but not sure where to look.]
>
> See src/include/catalog/indexing.h -- I don't remember if there's
> anything else that needs
Simon Riggs wrote:
> [BTW how do you add new indexes to system tables? I want to add one to
> pg_inherits but not sure where to look.]
See src/include/catalog/indexing.h -- I don't remember if there's
anything else that needs modification.
--
Alvaro Herrerahttp:/
On Thu, 2006-03-16 at 10:57 -0500, Tom Lane wrote:
> Simon Riggs <[EMAIL PROTECTED]> writes:
> > Trying to get the information in the wrong place would be very
> > expensive, I agree. But preparing that information when we have access
> > to it and passing it through the plan would be much cheaper.
Simon Riggs <[EMAIL PROTECTED]> writes:
> Trying to get the information in the wrong place would be very
> expensive, I agree. But preparing that information when we have access
> to it and passing it through the plan would be much cheaper.
Where would that be?
> The operator and the opclass are
On Wed, 2006-03-15 at 21:05 -0500, Tom Lane wrote:
> So we need a more accurate estimate for the boundary case.
Agreed.
> > Using 1.0e-10 isn't very useful... the selectivity for a range should
> > never be less than the selectivity for an equality, so we should simply
> > put in a test against o
Simon Riggs <[EMAIL PROTECTED]> writes:
>> ISTM that when the BETWEEN constants match we end up in this part of
>> clauselist_selectivity()...
Yeah, I think you are right.
> so that the planner underestimates the cost of using "Cal_CalDate" so
> that it ends up the same as "Cal_CtofcNo", and then
On Thu, 2006-03-16 at 00:07 +, Simon Riggs wrote:
> On Wed, 2006-03-15 at 14:17 -0500, Tom Lane wrote:
>
> > It looks to me like this is a matter of bad cost estimation, ie, it's
> > thinking the other index is cheaper to use. Why that is is not clear.
> > Can we see the pg_stats rows for cto
On Wed, 2006-03-15 at 14:17 -0500, Tom Lane wrote:
> It looks to me like this is a matter of bad cost estimation, ie, it's
> thinking the other index is cheaper to use. Why that is is not clear.
> Can we see the pg_stats rows for ctofcNo and calDate?
ISTM that when the BETWEEN constants match we
On 3/15/06, Andreas Kretschmer <[EMAIL PROTECTED]> wrote:
> Merlin Moncure <[EMAIL PROTECTED]> schrieb:
>
> > On 3/15/06, Kevin Grittner <[EMAIL PROTECTED]> wrote:
> > > Attached is a simplified example of a performance problem we have seen,
> > > with a workaround and a suggestion for enhancement
Merlin Moncure <[EMAIL PROTECTED]> schrieb:
> On 3/15/06, Kevin Grittner <[EMAIL PROTECTED]> wrote:
> > Attached is a simplified example of a performance problem we have seen,
> > with a workaround and a suggestion for enhancement (hence both the
> > performance and hackers lists).
>
>
> Hi Kevi
>>> On Wed, Mar 15, 2006 at 1:17 pm, in message
<[EMAIL PROTECTED]>,
Tom Lane <[EMAIL PROTECTED]> wrote:
>
> 8.1 is certainly capable of devising the plan you want, for example
> in the regression database:
>
> regression=# explain select * from tenk1 where thousand = 10 and
tenthous
> between
On 3/15/06, Kevin Grittner <[EMAIL PROTECTED]> wrote:
> Attached is a simplified example of a performance problem we have seen,
> with a workaround and a suggestion for enhancement (hence both the
> performance and hackers lists).
Hi Kevin. In postgres 8.2 you will be able to use the row-wise
co
"Kevin Grittner" <[EMAIL PROTECTED]> writes:
>> Odd. Can you tell us your PG- Version?
> this is 8.1.2 with some 8.1.3 changes plus the string literal patch.)
8.1 is certainly capable of devising the plan you want, for example
in the regression database:
regression=# explain select * from tenk1
>>> On Wed, Mar 15, 2006 at 12:17 pm, in message
<[EMAIL PROTECTED]>, Andreas Kretschmer
<[EMAIL PROTECTED]> wrote:
> Kevin Grittner <[EMAIL PROTECTED]> schrieb:
>
>> Attached is a simplified example of a performance problem we have
seen,
>
> Odd. Can you tell us your PG- Version?
I know we rea
Kevin Grittner <[EMAIL PROTECTED]> schrieb:
> Attached is a simplified example of a performance problem we have seen,
Odd. Can you tell us your PG-Version?
Andreas
--
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect.
Attached is a simplified example of a performance problem we have seen,
with a workaround and a suggestion for enhancement (hence both the
performance and hackers lists).
Our software is allowing users to specify the start and end dates for a
query. When they enter the same date for both, the opt
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