From: Jim Posen <jim.posen@gmail•com>
To: pieter.wuille@gmail•com,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Minimizing the redundancy in Golomb Coded Sets
Date: Tue, 29 May 2018 15:38:01 -0700 [thread overview]
Message-ID: <CADZtCShF-sGNfjSaOdmK=YMOdvimN2b_a1vXmJv_XHKxvn14Zw@mail.gmail.com> (raw)
In-Reply-To: <CAAS2fgQSS7R+PtmpcXJqjeXWnLa8S8O_1nFgdCYiLqRYbQM3QQ@mail.gmail.com>
[-- Attachment #1.1: Type: text/plain, Size: 1497 bytes --]
This is a really cool finding, thanks Pieter!
I did some more analysis on selecting a good P value to reduce total data
downloaded considering both filters themselves and blocks in the case of
false positive matches, using data from mainnet. The quantity it minimizes
is:
filter_size(N, B) + block_size * false_positive_probability(C, N, B)
N is the number of filter elements per block
B is the Golomb-Rice coding parameter
C is the number of filter elements watched by the client
The main result is that:
For C = 10, B = 13 is optimal
For C = 100, B = 16 is optimal
For C = 1,000, B = 20 is optimal
For C = 10,000, B = 23 is optimal
So any value of B in the range 16 to 20 seems reasonable, with M = 1.4971 *
2^B for optimal compression, as Pieter derived. The selection of the
parameter depends on the target number of elements that a client may watch.
I attached some of the results, and would be happy to share the CSV and raw
notebook if people are interested.
On Fri, May 25, 2018 at 2:14 PM Gregory Maxwell via bitcoin-dev <
bitcoin-dev@lists•linuxfoundation.org> wrote:
> On Fri, May 25, 2018 at 6:42 PM, Gregory Maxwell <greg@xiph•org> wrote:
> > configuration is roughly right, then M=1569861 and rice parameter 19
> > should be used.
>
> That should have been M=784931 B=19 ... paste error.
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists•linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
[-- Attachment #1.2: Type: text/html, Size: 3477 bytes --]
[-- Attachment #2: Filter FP Rate.html --]
[-- Type: text/html, Size: 297617 bytes --]
next prev parent reply other threads:[~2018-05-29 22:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-25 17:54 Pieter Wuille
2018-05-25 18:42 ` Gregory Maxwell
2018-05-25 21:13 ` Gregory Maxwell
2018-05-29 22:38 ` Jim Posen [this message]
2018-05-30 3:10 ` Lucas Ontivero
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CADZtCShF-sGNfjSaOdmK=YMOdvimN2b_a1vXmJv_XHKxvn14Zw@mail.gmail.com' \
--to=jim.posen@gmail$(echo .)com \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=pieter.wuille@gmail$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox