From:
Greg Stark <gsstark(at)mit(dot)edu>
To:
Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
Cc:
Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, David Fetter <david(at)fetter(dot)org>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject:
Re: wip: functions median and percentile
Date:
2010-10-03 15:49:37
Message-ID:
AANLkTimMoQpzCoL1OLASh0B5KPOG8tAm-3y=PhxbZS4y@mail.gmail.com (view raw or flat )
Thread:
2010-08-19 10:59:33 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-08-19 14:50:23 from Greg Stark <gsstark(at)mit(dot)edu>
2010-08-19 15:33:13 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-08-19 16:49:45 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-08-19 17:03:20 from David Fetter <david(at)fetter(dot)org>
2010-08-19 17:12:12 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2010-08-19 17:14:58 from David Fetter <david(at)fetter(dot)org>
2010-08-19 17:25:36 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-08-19 17:47:59 from David Fetter <david(at)fetter(dot)org>
2010-08-19 18:17:42 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-08-19 17:41:57 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-08-19 18:17:28 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2010-08-19 17:38:14 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-20 03:47:09 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-09-20 05:11:02 from David Fetter <david(at)fetter(dot)org>
2010-09-20 06:22:29 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-21 20:28:15 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-21 20:44:16 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-21 21:03:31 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-22 02:21:01 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-09-22 04:36:24 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-22 03:06:51 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-09-22 04:44:58 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-23 09:35:47 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-23 17:45:36 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-09-23 18:27:38 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-23 18:48:47 from David Fetter <david(at)fetter(dot)org>
2010-09-23 18:56:53 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-26 10:39:21 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-01 08:17:19 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-01 08:46:45 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-01 13:05:43 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-01 13:19:57 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-01 14:11:08 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-01 14:43:47 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-01 15:00:35 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-01 15:08:00 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-01 15:15:03 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2010-10-01 15:35:03 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-01 15:16:03 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-01 15:22:46 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-01 15:32:03 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-01 17:37:03 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-01 19:17:08 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-03 14:06:25 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-03 15:49:37 from Greg Stark <gsstark(at)mit(dot)edu>
2010-10-04 06:36:48 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-04 06:58:44 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-04 16:14:06 from Greg Stark <gsstark(at)mit(dot)edu>
2010-10-04 17:22:39 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-10-04 19:20:28 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-05 06:04:31 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-05 08:47:52 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-05 12:14:24 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-05 13:08:59 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-10 21:16:59 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 06:58:53 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-11 09:35:13 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 09:55:16 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-11 10:33:11 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 14:03:40 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 15:30:46 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 15:44:08 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 17:34:51 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 17:37:11 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 17:42:10 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 17:48:12 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 17:55:32 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 18:05:11 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 18:23:25 from Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
2010-10-11 10:33:12 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-10-11 14:08:53 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-10-11 14:29:38 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-10-11 18:27:13 from Greg Stark <gsstark(at)mit(dot)edu>
2010-10-11 18:30:39 from Josh Berkus <josh(at)agliodbs(dot)com>
2010-10-11 18:46:47 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-12 03:08:32 from Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
2010-10-12 08:44:20 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-13 10:36:59 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-13 10:48:17 from Peter Eisentraut <peter_e(at)gmx(dot)net>
2010-10-13 10:51:51 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-13 10:56:06 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-14 00:54:42 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-10-14 02:37:37 from Greg Stark <gsstark(at)mit(dot)edu>
2010-10-14 12:17:54 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-10-14 04:53:57 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-03 17:31:18 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-10-01 14:44:44 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-23 13:22:39 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
2010-09-23 13:25:32 from Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
Lists:
pgsql-hackers pgsql-rrreviewers
On Sun, Oct 3, 2010 at 7:06 AM, Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com> wrote:
> And I'm now thinking about how to make median happen in window
> aggregate.
If you were to do this by extending tuplesort what extra features
would tuplesort need?
Would tuplesort need the ability to insert additional records into an
already sorted array and maintain the sort?
Would it need the ability to remove records from the sorted set?
Would it need the ability to do a partial sort (the QuickSelect algorithm)?
The ability to do random access on disk sets?
How do existing windowed aggregates work if you specify an order by on
the aggregate? Do they resort for every output row?
Does the spec give a way to run an arbitrary subselect on the current
window? I wonder if we need more powerful machinery anyways to handle
these cases.
--
greg
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