From: Joshua Marsh <icub3d@gmail.com>
To: pgsql-performance@postgresql.org
Subject: Re: Hints proposal
Date: Thu, 12 Oct 2006 09:26:24 -0600
Message-ID: <38242de90610120826l5328759bt41468644e54badae@mail.gmail.com> (raw)
In-Reply-To: <20061012151439.GT28647@nasby.net>
References: <20061012151439.GT28647@nasby.net>
On 10/12/06, Jim C. Nasby <jim@nasby.net> wrote:
>
> Posting here instead of hackers since this is where the thread got
> started...
>
> The argument has been made that producing a hints system will be as hard
> as actually fixing the optimizer. There's also been clamoring for an
> actual proposal, so here's one that (I hope) wouldn't be very difficult
> to implemen.
>
> My goal with this is to keep the coding aspect as simple as possible, so
> that implementation and maintenance of this isn't a big burden. Towards
> that end, these hints either tell the planner specifically how to handle
> some aspect of a query, or they tell it to modify specific cost
> estimates. My hope is that this information could be added to the
> internal representation of a query without much pain, and that the
> planner can then use that information when generating plans.
I've been following the last thread with a bit of interest. I like the
proposal. It seems simple and easy to use. What is it about hinting that
makes it so easily breakable with new versions? I don't have any experience
with Oracle, so I'm not sure how they screwed logic like this up. Hinting
to use a specific merge or scan seems fairly straight forward; if the query
requests to use an index on a join, I don't see how hard it is to go with
the suggestion. It will become painfully obvious to the developer if his
hinting is broken.
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To: pgsql-performance@postgresql.org
Cc: icub3d@gmail.com
Subject: Re: Hints proposal
In-Reply-To: <38242de90610120826l5328759bt41468644e54badae@mail.gmail.com>
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