From: Heikki Linnakangas <heikki@enterprisedb.com>
To: Ron Mayer <rm_pg@cheapcomplexdevices.com>
Cc: pgsql-patches@postgresql.org
Subject: Re: [HACKERS] Maintaining cluster order on insert
Date: Sat, 12 Aug 2006 00:16:58 +0100
Message-ID: <44DD0FEA.8070002@enterprisedb.com> (raw)
In-Reply-To: <ebipoh$1538$1@news.hub.org>
References: <44DA31B1.3090700@enterprisedb.com>
<28914.1155154622@sss.pgh.pa.us>
<36e682920608091347m4e075a8cv6a04e3c4d97ed6f4@mail.gmail.com>
<430d92a20608091831w6e59da84k48a58110cb98e8d6@mail.gmail.com>
<9461.1155178183@sss.pgh.pa.us>
<ebipoh$1538$1@news.hub.org>
Ron Mayer wrote:
> In my case my biggest/slowest tables are clustered by zip-code (which
> does a reasonable job at keeping counties/cities/etc on the
> same pages too). Data comes in constantly (many records per minute, as
> we ramp up), pretty uniformly across the country; but most queries
> are geographically bounded. The data's pretty much insert-only.
No deletes? If the tables grow over time, you probably would need to run
CLUSTER every now and then to get the best performance, though the patch
would alleviate that quite a lot.
Do you have a development environment where you could test what effect
the patch would have? It would be interesting to have a real-world use
case, since I don't have one myself at the moment.
> If I understand Heikki's patch, it would help for this use case.
Yes, it would.
> > Your best bet might be to partition the table into two subtables, one
> > with "stable" data and one with the fresh data, and transfer rows from
> > one to the other once they get stable. Storage density in the "fresh"
> > part would be poor, but it should be small enough you don't care.
>
> Hmm... that should work well for me too. Not sure if the use-case
> I mentioned above is still compelling anymore; since this seems like
> it'd give me much of the benefit; and I don't need an excessive
> fillfactor on the stable part of the table.
Umm, if your inserts are uniformly distributed across the country, you
wouldn't have a stable part, right?
- Heikki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: heikki@enterprisedb.com, rm_pg@cheapcomplexdevices.com, pgsql-patches@postgresql.org
Subject: Re: [HACKERS] Maintaining cluster order on insert
In-Reply-To: <44DD0FEA.8070002@enterprisedb.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox