Content-Type: text/plain; charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 10.2 \(3259\))
From: Johnson Lau <jl2012@xbt.hk>
In-Reply-To: <1491681378.2454247.938587616.7199D633@webmail.messagingengine.com>
Date: Sun, 9 Apr 2017 04:21:04 +0800
Content-Transfer-Encoding: quoted-printable
Message-Id: <DF7A05F0-4EA7-4CB3-A9BE-491BDA209EF7@xbt.hk>
References: <1491516747.3791700.936828232.69F82904@webmail.messagingengine.com>
	<CAAS2fgTJ8xOj8zCmBq1LN9OdMV-tDfSjVUPhLpO98cR1w-QAoA@mail.gmail.com>
	<CA+KqGko0cDY29bhznMxJJ7yAUTuB6GaDDNGBRwzssJUxM_53xQ@mail.gmail.com>
	<1491599691.1245876.937920664.6EBA20DC@webmail.messagingengine.com>
	<CAAS2fgTWyX5M-xcELC2vDvGfs01tbGYkpZJCSeNbvn_p4Ecjqg@mail.gmail.com>
	<1491636528.2474173.938219072.54C44183@webmail.messagingengine.com>
	<6F1E6FB6-1342-4BD6-BF83-A160C1A7CD34@xbt.hk>
	<1491681378.2454247.938587616.7199D633@webmail.messagingengine.com>
To: Tomas <tomas@tomasvdw.nl>
Cc: bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Using a storage engine without UTXO-index
Precedence: list


> On 9 Apr 2017, at 03:56, Tomas <tomas@tomasvdw.nl> wrote:
>=20
>=20
>> I don=E2=80=99t fully understand your storage engine. So the =
following deduction
>> is just based on common sense.
>>=20
>> a) It is possible to make unlimited number of 1-in-100-out txs
>>=20
>> b) The maximum number of 100-in-1-out txs is limited by the number of
>> previous 1-in-100-out txs
>>=20
>> c) Since bitcrust performs not good with 100-in-1-out txs, for =
anti-DoS
>> purpose you should limit the number of previous 1-in-100-out txs.=20
>>=20
>> d) Limit 1-in-100-out txs =3D=3D Limit UTXO growth
>>=20
>> I=E2=80=99m not surprised that you find an model more efficient than =
Core. But I
>> don=E2=80=99t believe one could find a model that doesn=E2=80=99t =
become more efficient
>> with UTXO growth limitation.
>=20
> My efficiency claims are *only* with regards to order validation. If =
we
> assume all transactions are already pre-synced and verified, =
bitcrust's
> order validation is very fast, and (only slightly) negatively effected
> by input-counts.

pre-synced means already in mempool and verified? Then it sounds like we =
just need some mempool optimisation? The tx order in a block is not =
important, unless they are dependent

>=20
>> One more question: what is the absolute minimum disk and memory usage =
in
>> bitcrust, compared with the pruning mode in Core?
>=20
> As bitcrust doesn't support this yet, I cannot give accurate numbers,
> but I've provided some numbers estimates earlier in the thread.
>=20
>=20
> Rereading my post and these comments, I may have stepped on some toes
> with regards to SegWit's model. I like SegWit (though I may have a
> slight preference for BIP140), and I understand the reasons for the
> "discount", so this was not my intention. I just think that the =
reversal
> of costs during peak load order validation is a rather interesting
> feature of using spend-tree  based validation.=20
>=20
> Tomas

Please no conspiracy theory like stepping on someone=E2=80=99s toes. I =
believe it=E2=80=99s always nice to challenge the established model. =
However, as I=E2=80=99m trying to make some hardfork design, I intend to =
have a stricter UTXO growth limit. As you said "protocol addressing the =
UTXO growth, might not be worth considering protocol improvements*, it =
sounds like UTXO growth limit wouldn=E2=80=99t be very helpful for your =
model, which I doubt.=20=