Re: Big disappointment with Postgres
From: Serge Rielau <srielau_at_ca.ibm.com>
Date: Sun, 13 Feb 2011 09:19:06 -0500
Message-ID: <8rq7imFacfU1_at_mid.individual.net>
On 2/13/2011 7:51 AM, Jonathan Lewis wrote:
> Which brings us back to the need for hints even for very simple queries -
> when my
> question was: "how do you do it without hinting".
I don't think we differ conceptually.
My point is that the hint should supply the missing information (e.g. selectivity) and not dictate the plan.
It's still a hint.
Date: Sun, 13 Feb 2011 09:19:06 -0500
Message-ID: <8rq7imFacfU1_at_mid.individual.net>
On 2/13/2011 7:51 AM, Jonathan Lewis wrote:
> Which brings us back to the need for hints even for very simple queries -
> when my
> question was: "how do you do it without hinting".
I don't think we differ conceptually.
My point is that the hint should supply the missing information (e.g. selectivity) and not dictate the plan.
It's still a hint.
BTW, the IBM position (which may or may not match mine) is that the user tells support (i.e. last resort) that they are stuck and support provides the hint (i.e. no need to wait for a patch). If hints are truly rarely needed then this ought to be an acceptable compromise between idealism and pragmatism.
Cheers
Serge
-- Serge Rielau SQL Architect DB2 for LUW, IBM Toronto Lab Blog: tinyurl.com/SQLTips4DB2 Wiki: tinyurl.com/Oracle2DB2Wiki Twitter: srielauReceived on Sun Feb 13 2011 - 08:19:06 CST