Re: Index overhead cost reporting

From: Thom Brown <thom(at)linux(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Index overhead cost reporting
Date: 2013-12-07 20:50:12
Message-ID: CAA-aLv571jcZMOauAhWV8GoOpNXx8FaoHtQa9CEoPjcW3s_5Xg@mail.gmail.com
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On 7 December 2013 20:44, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Thom Brown <thom(at)linux(dot)com> writes:
>> So in essence, I'd only be looking for a breakdown of anything that
>> adds to the duration of the DML statement. However, it sounds like
>> even that isn't straightforward from what you've written.
>
> I think that would be reasonably straightforward, though perhaps too
> expensive depending on the speed of clock reading. My larger point was
> that I don't think that that alone is a fair measure of the cost of
> maintaining an index, which is what you had claimed to be interested in.

Point taken. Yes, I don't believe I was that clear. This was a "how
much of my DML statement time was spent updating indexes" rather than
a "give me stats on index maintenance times for these indexes".

It's a shame that it comes at a non-trivial price.

Thom

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