Re: PGA_AGGREGATE_TARGET sizing of work areas and HJ cost

From: joel garry <>
Date: Fri, 29 May 2009 12:16:58 -0700 (PDT)
Message-ID: <>

On May 29, 10:45 am, "Jonathan Lewis" <> wrote:

> Joel,
> From the way the OP asks the question I don't think he had the
> parameter hash_area_size in mind; to me it sounded like a
> question about "how is the equivalent of the hash_area_size
> derived when using automatic workarea sizing".

From his reply to John, that's even less clear to me. I have no problem with myself or anyone misreading any of this, I think it is a good thing that people are willing to fill in the blanks. I read John's reply as asking if he's even using bind variables, it's only in the context of histograms that "using bind variables" becomes sensible as a plan changer. No offense intended towards Gregor, he needed a lot more info in the original post - histograms might make all the difference here, and his subsequent post references manipulating hash_area_size, perhaps as a way of telling John he knows about binds - or perhaps he is too quick to eliminate histograms as an issue. So I for one am confused about exactly what he is trying, and what level of expertise he has. You are probably less confused than me in general :-) but we need more details, replicable case, blabla, if anyone even really cares about 9.2. But of course, there may be something interesting here in more recent versions, too.


-- is bogus.
Received on Fri May 29 2009 - 14:16:58 CDT

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