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From Dmitriy Setrakyan <dsetrak...@apache.org>
Subject Re: Custom string encoding
Date Mon, 03 Jul 2017 14:21:08 GMT
Agree with Valya on the system-wide default. We need to have it.

Also, are we certain that the encoding will provide 1-byte length for UTF-8
for different languages? Would be nice to test it to confirm, as it has a
potential to decrease the Ignite storage space by 2x in certain cases.

D.

On Sun, Jul 2, 2017 at 12:26 PM, Valentin Kulichenko <
valentin.kulichenko@gmail.com> wrote:

> Vova,
>
> That's actually a good point. Probably that would be enough and there is no
> need to introduce absract encoder. However, I still think it makes sense to
> specify default encoding in BinaryConfiguration and
> BinaryTypeConfiguration.
>
> -Val
>
> On Sun, Jul 2, 2017 at 10:31 AM Vladimir Ozerov <vozerov@gridgain.com>
> wrote:
>
> > Yes, this is exactly what non-UTF8 encodings do.
> >
> > вс, 2 июля 2017 г. в 20:08, Dmitriy Setrakyan <dsetrakyan@apache.org>:
> >
> > > On Sun, Jul 2, 2017 at 9:50 AM, Vladimir Ozerov <vozerov@gridgain.com>
> > > wrote:
> > >
> > > > There is no need for custom encoders, as they are already built-in to
> > > Java.
> > > >
> > >
> > > Will non-ASCII encodings fit into 1 byte? The whole point here is to
> save
> > > space.
> > >
> > >
> > > >
> > > > вс, 2 июля 2017 г. в 19:16, Dmitriy Setrakyan <dsetrakyan@apache.org
> >:
> > > >
> > > > > Vladimir, how would you plugin custom encoders in your design?
> > > > >
> > > > > On Sat, Jul 1, 2017 at 11:53 PM, Vladimir Ozerov <
> > vozerov@gridgain.com
> > > >
> > > > > wrote:
> > > > >
> > > > > > Valya,
> > > > > >
> > > > > > Personally I vote against this feature. BinaryConfiguration
is
> > proven
> > > > to
> > > > > be
> > > > > > inconvenient, since it has to be configured before node start,
it
> > > > cannot
> > > > > be
> > > > > > changed in runtime, and it requires classes on the server.
> > Moreover,
> > > if
> > > > > you
> > > > > > decide to change encoding at some point, it would be impossible.
> > > > > >
> > > > > > I think, we should add this feature on API level instead. If
> string
> > > is
> > > > > > written in non-UTF8 form, we will write in different format:
> > > > > > [encoding_code][string]
> > > > > >
> > > > > > BInaryWriter.writeString(String fieldName, String val);
> > > > > > BInaryWriter.writeString(String fieldName, String val, *String
> > > > > encoding*);
> > > > > >
> > > > > > BinaryReader.readString(String fieldName);
> > > > > > BinaryReader.readString(String fieldName, *String encoding*);
> > > > > >
> > > > > > BinaryObjectBuilder.writeString(String fieldName, String val,
> > *String
> > > > > > encoding*);
> > > > > >
> > > > > > class MyClass {
> > > > > >     *@BinaryString(encoding = "Cp1251")*
> > > > > >     private String myCyrillicString;
> > > > > > }
> > > > > >
> > > > > > Vladimir.
> > > > > >
> > > > > > On Sat, Jul 1, 2017 at 7:26 PM, Dmitriy Setrakyan <
> > > > dsetrakyan@apache.org
> > > > > >
> > > > > > wrote:
> > > > > >
> > > > > > > On Sat, Jul 1, 2017 at 2:24 AM, Sergi Vladykin <
> > > > > sergi.vladykin@gmail.com
> > > > > > >
> > > > > > > wrote:
> > > > > > >
> > > > > > > > In SQL indexes we may store partial strings and assume
them
> to
> > be
> > > > in
> > > > > > > UTF-8,
> > > > > > > > I don't think this can be abstracted away. But may
be this is
> > > not a
> > > > > big
> > > > > > > > deal if in indexes we still will use UTF-8.
> > > > > > > >
> > > > > > >
> > > > > > > Sergi, why does it matter if it is UTF8 or custom encoding?
Why
> > > can't
> > > > > we
> > > > > > > use our own compact encoding in indexes?
> > > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > 2017-07-01 10:13 GMT+03:00 Dmitriy Setrakyan <
> > > > dsetrakyan@apache.org
> > > > > >:
> > > > > > > >
> > > > > > > > > Val, do you know how we compare strings in SQL
queries?
> Will
> > we
> > > > be
> > > > > > able
> > > > > > > > to
> > > > > > > > > use this encoder?
> > > > > > > > >
> > > > > > > > > Additionally, I think that the encoder is a bit
too
> abstract.
> > > Why
> > > > > not
> > > > > > > go
> > > > > > > > > even further and allow users create their own
ASCII table
> for
> > > > > > encoding?
> > > > > > > > >
> > > > > > > > > D.
> > > > > > > > >
> > > > > > > > > On Fri, Jun 30, 2017 at 6:49 PM, Valentin Kulichenko
<
> > > > > > > > > valentin.kulichenko@gmail.com> wrote:
> > > > > > > > >
> > > > > > > > > > Andrey,
> > > > > > > > > >
> > > > > > > > > > Can you elaborate more on this? What is
your concern?
> > > > > > > > > >
> > > > > > > > > > -Val
> > > > > > > > > >
> > > > > > > > > > On Fri, Jun 30, 2017 at 6:17 PM Andrey Mashenkov
<
> > > > > > > > > > andrey.mashenkov@gmail.com>
> > > > > > > > > > wrote:
> > > > > > > > > >
> > > > > > > > > > > Val,
> > > > > > > > > > >
> > > > > > > > > > > Looks like make sense.
> > > > > > > > > > >
> > > > > > > > > > > This will not affect FullText index,
as Lucene has own
> > > format
> > > > > for
> > > > > > > > > storing
> > > > > > > > > > > data.
> > > > > > > > > > >
> > > > > > > > > > > But.. would it be compatible with H2
indexing ? I
> doubt.
> > > > > > > > > > >
> > > > > > > > > > > 1 июля 2017 г. 2:27 пользователь
"Valentin Kulichenko"
> <
> > > > > > > > > > > valentin.kulichenko@gmail.com> написал:
> > > > > > > > > > >
> > > > > > > > > > > > Folks,
> > > > > > > > > > > >
> > > > > > > > > > > > Currently binary marshaller always
encodes strings in
> > > > UTF-8.
> > > > > > > > However,
> > > > > > > > > > > > sometimes it can be useful to
customize this. For
> > > example,
> > > > if
> > > > > > > data
> > > > > > > > > > > contains
> > > > > > > > > > > > a lot of Cyrillic, Chinese or
other symbols, but not
> so
> > > > many
> > > > > > > Latin
> > > > > > > > > > > symbols,
> > > > > > > > > > > > memory is used very inefficiently.
In this case it
> > would
> > > be
> > > > > > great
> > > > > > > > to
> > > > > > > > > > > encode
> > > > > > > > > > > > most frequently used symbols in
one byte instead of
> two
> > > or
> > > > > > three.
> > > > > > > > > > > >
> > > > > > > > > > > > I propose to introduce BinaryStringEncoder
interface
> > that
> > > > > will
> > > > > > > > > convert
> > > > > > > > > > > > strings to byte arrays and back,
and make it
> pluggable
> > > via
> > > > > > > > > > > > BinaryConfiguration. This will
allow users to plug in
> > any
> > > > > > > encoding
> > > > > > > > > > > > algorithms based on their requirements.
> > > > > > > > > > > >
> > > > > > > > > > > > Thoughts?
> > > > > > > > > > > >
> > > > > > > > > > > > https://issues.apache.org/jira/browse/IGNITE-5655
> > > > > > > > > > > >
> > > > > > > > > > > > -Val
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

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