From: MichaelDBA <MichaelDBA@sqlexec.com>
To: Andreas Karlsson <andreas@proxel.se>
Cc: pgsql-performance@lists.postgresql.org <pgsql-performance@lists.postgresql.org>
Subject: Re: Indexes on UUID - Fragmentation Issue
Date: Mon, 29 Oct 2018 15:12:09 -0400
Message-ID: <5BD75B89.6040305@sqlexec.com> (raw)
In-Reply-To: <2d34b6d8-a22f-e5de-1cbe-f92012006de9@proxel.se>
References: <CAFowjW1J7KMjPfQY0ST94V0t=rcjz13HkjMuqJVP_Lk6Zn8Cag@mail.gmail.com>
<2d34b6d8-a22f-e5de-1cbe-f92012006de9@proxel.se>
or prepend the UUID with a timestamp?
Regards,
Michael Vitale
> Andreas Karlsson <mailto:andreas@proxel.se>
> Monday, October 29, 2018 10:52 AM
> On 10/29/2018 02:29 PM, Uday Bhaskar V wrote:> I have
>
> How is it implemented? I can personally see two ways of generating
> sequential UUID:s. Either you use something like PostgreSQL's
> sequences or you can implement something based on the system time plus
> some few random bits which means they will be mostly sequential.
>
> It could be worth checking on the hackers mailing list if there is any
> interest in this feature, but if it works like a sequence it should
> also probably be a sequence if it is ever going to be accepted into
> the core.
>
> For your own use I recommend doing like Merlin suggested and write an
> extension. As long as you know a bit of C they are easy to write.
>
> Andreas
>
> Uday Bhaskar V <mailto:uday.bhaskar579@gmail.com>
> Monday, October 29, 2018 9:29 AM
> Hi,
>
> I have searched in many postgres blogs for Sequential UUID generation,
> which can avoid Fragmentation issue.
>
> I did a POC(in postgres) with sequential UUID against Non sequential
> which has shown lot of different in space utilization and index size.
> Sql server has "newsequentialid" which generates sequential UUID. I
> have created C function which can generate a sequential UUID, but I am
> not sure how best I can use that in postgres.
>
> I would really like to contribute to Postgres, If I can. Please let me
> know your thoughts or plans regarding UUID generation.
>
> Regards,
> Uday
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To: pgsql-performance@postgresql.org
Cc: MichaelDBA@sqlexec.com, andreas@proxel.se, pgsql-performance@lists.postgresql.org
Subject: Re: Indexes on UUID - Fragmentation Issue
In-Reply-To: <5BD75B89.6040305@sqlexec.com>
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