Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
![]() |
![]() |
Home -> Community -> Mailing Lists -> Oracle-L -> RE: trouble with sql
this does yield a somewhat better execution plan.
i was just thinking there was some way (possibly/probably through analytics) to pull the value of column 4 without having to do a self join.
thanks for the help!
chris
From: Boyle, Christopher [mailto:Christopher.Boyle_at_MultiPlan.com] Sent: Wednesday, January 03, 2007 3:33 PM To: Stephens, Chris; oracle-l_at_freelists.org Subject: RE: trouble with sql
Okay, this might have a better explain plan (assuming 9i or above)
with ps2 as ( select/*+ materialize */ p.periodID, ps.projectNumber, max(ps.changeDate) as changeDate
from period p, projectStatus ps
where ps.changeDate >= trunc( p.startDate )
and trunc( ps.changeDate ) <= p.endDate
group by p.periodID, ps.projectNumber )
select ps2.periodID, ps2.projectNumber, ps2.changeDate, ps3.statusID
from ps2, projectStatus ps3
where ps2.projectNumber = ps3.projectNumber and ps2.changeDate = ps3.changeDate;
but I cant tell without table definitions. Can a project have more than one active status? From the query I would guess that the max change date indicates the current status but I am not sure. Can periods overlap?
Chris
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Stephens, Chris
Sent: Wednesday, January 03, 2007 3:34 PM
To: oracle-l_at_freelists.org
Subject: trouble with sql
There has got to be a way to do this but I can't find the syntax.
Essentially I need the max of column 3 grouped by column 1 and 2 and also the value of column 4 that corresponds to the returned columns 1,2, and 3.
Here is the actual sql that I believe to be using an unnecessary join:
select ps2.periodID, ps2.projectNumber, ps2.changeDate, ps3.statusID
from ( select p.periodID, ps.projectNumber, max(ps.changeDate) as
changeDate
from period p, projectStatus ps
where ps.changeDate >= trunc( p.startDate )
and trunc( ps.changeDate ) <= p.endDate group by p.periodID, ps.projectNumber ) ps2, projectStatus ps3 where ps2.projectNumber = ps3.projectNumber and ps2.changeDate = ps3.changeDate
Is there a better way to write this?
CONFIDENTIALITY NOTICE:
This message is intended for the use of the individual or entity to
which it is addressed and may contain information that is privileged,
confidential and exempt from disclosure under applicable law. If the
reader of this message is not the intended recipient or the employee or
agent responsible for delivering this message to the intended recipient,
you are hereby notified that any dissemination, distribution or copying
of this communication is strictly prohibited. If you have received this
communication in error, please notify us immediately by email reply.
NOTICE OF CONFIDENTIALITY: Information included in and/or attached to this electronic mail transmission may be confidential. This electronic mail transmission is intended for the addressee(s) only. Any unauthorized disclosure, reproduction, or distribution of, and/or any unauthorized action taken in reliance on the information in this electronic mail is prohibited. If you believe that you have received this electronic mail transmission in error, please notify the sender by reply transmission, or contact helpdesk_at_multiplan.com <mailto:helpdesk_at_multiplan.com> , and delete the message without copying or disclosing it.
CONFIDENTIALITY NOTICE:
This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged,
confidential and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this
communication in error, please notify us immediately by email reply.
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Jan 03 2007 - 15:43:44 CST
![]() |
![]() |