Managing encoding on per-cache level is not that complex thing. Essentially, when any cache message are prepared on initiating node, we perform Object -> BinaryObject transition. These places has reference to cache context ([1], [2]). This is where we should define proper string encoding - either take global encoding, or cache-specific encoding.
As far as per-column encoding, let's put this fine-grained case aside for a while. This is not as widely used as global or per-cache/per-table scenario. [1] org.apache.ignite.internal.processors.cache.GridCacheContext#toCacheKeyObject(java.lang.Object) [2] org.apache.ignite.internal.processors.cache.GridCacheContext#toCacheObject On Fri, Jul 28, 2017 at 8:08 PM, Artem Schitow <artem.schi...@gmail.com> wrote: > > String encoding is a concept similar to "collation" in RDBMS. You can > > define it either globally, or on per-table basis. > > Or on per-column (per-field) basis. Though Oracle does not have per-column > charset, some other databases provide this option. > > MySQL: > - https://dev.mysql.com/doc/refman/5.7/en/create-table.html > | CHAR[(length)] [BINARY] > [CHARACTER SET charset_name] [COLLATE collation_name] > > | VARCHAR(length) [BINARY] > [CHARACTER SET charset_name] [COLLATE collation_name] > > | TEXT [BINARY] > [CHARACTER SET charset_name] [COLLATE collation_name] > > SQL Server: > - https://docs.microsoft.com/en-us/sql/t-sql/statements/ > create-table-transact-sql > <column_definition> ::= > column_name <data_type> > [ FILESTREAM ] > [ COLLATE collation_name ] > > Postgres: > - https://www.postgresql.org/docs/9.6/static/sql-createtable.html > CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF > NOT EXISTS ] table_name > ( [ > { > column_name data_type [ COLLATE collation ] > > > 1) I have a class Person with field "name". I have two caches/tables - > one > > for US persons, where name is in Latin, another for RU persons with > > Cyrillic names. How can achieve optimal encoding formats for both tables? > > You have to have two classes in this case, maybe with a common parent. Or > you have to select a common denominator and settle with one encoding for > both of them. Like Java did with UTF-16 java.util.String-s. > > — > Artem Schitow > artem.schi...@gmail.com > > > > > > On 28 Jul 2017, at 14:45, Vladimir Ozerov <voze...@gridgain.com> wrote: > > > > String encoding is a concept similar to "collation" in RDBMS. You can > > define it either globally, or on per-table basis. The same should be done > > for Ignite. We do not define behavior of a type. We define behavior of a > > *storage*. > > > > Two cases when proposed approach with per-type and per-type-field > approach > > doesn't work: > > 1) I have a class Person with field "name". I have two caches/tables - > one > > for US persons, where name is in Latin, another for RU persons with > > Cyrillic names. How can achieve optimal encoding formats for both tables? > > 2) I have an empty grid. Now I want to create a cache/table with custom > > encoding. How can I do that without cluster restart? Nohow, because > > BinaryTypeConfiguration configured statically, while caches/tables can be > > created in runtime. > > > > On Fri, Jul 28, 2017 at 2:38 PM, Pavel Tupitsyn <ptupit...@apache.org> > > wrote: > > > >>> As Pavel mentioned, Marshaller should not be tied to cache > >>> should be added to per-cache level > >> Not sure if I follow. > >> Marshalling and caching are two separate mechanisms. > >> Defining binary format in CacheConfiguration violates separation of > >> concerns. > >> > >>> Encoding *must not* be added to per-class or per-field level, this is > >> wrong > >> What is wrong with this? BinaryTypeConfiguration looks the right place > for > >> such a setting. > >> Are we talking from SQL standpoint here, so you want this to be defined > >> somehow via DDL in future? > >> > >> On Fri, Jul 28, 2017 at 2:30 PM, Vladimir Ozerov <voze...@gridgain.com> > >> wrote: > >> > >>> Encoding *must not* be added to per-class or per-field level, this is > >>> wrong. > >>> > >>> It should be added to per-cache level, and to per-cache-column level in > >>> future. > >>> > >>> пт, 28 июля 2017 г. в 14:27, Andrey Kuznetsov <stku...@gmail.com>: > >>> > >>>> We discussed this with Pavel and Anton just a moment ago. Summary > >>> follows. > >>>> > >>>> - New byte "flag" is to be added (ENCODED_STRING) > >>>> - 'Encoding' property is to be added at > >>>> -- global level (BinaryConfiguration) > >>>> -- per-class level (BinaryTypeConfiguration) > >>>> -- per-field level (BinaryTypeConfiguration) > >>>> > >>>> 2017-07-28 14:15 GMT+03:00 Vladimir Ozerov [via Apache Ignite > >>> Developers] < > >>>> ml+s2346864n20159...@n4.nabble.com>: > >>>> > >>>>> As Pavel mentioned, Marshaller should not be tied to cache, > >>> BinaryObject > >>>>> should be self-explanatory, i.e. containing all information necessary > >>> for > >>>>> unmarshalling. This is an absolute requirement. > >>>>> > >>>>> We will have one extra byte for in serialized form, meaning that > >>>> advantage > >>>>> of custom encoding will become evident for all strings with length >= > >>> 1, > >>>>> which is perfectly fine. I do not quite understand what are we > >> arguing > >>>>> about. > >>>>> > >>>>> As far as configuration, we can do it as follows: > >>>>> > >>>>> 1) Add global encoding, UTF8 by default. > >>>>> 2) Add per-cache encoding. > >>>>> 3) Add encoding to JDBC and ODBC driver properties. > >>>>> > >>>>> This should be enough. > >>>>> > >>>>> > >>>> -- > >>>> Best regards, > >>>> Andrey Kuznetsov. > >>>> > >>>> > >>>> > >>>> > >>>> -- > >>>> View this message in context: > >>>> http://apache-ignite-developers.2346864.n4.nabble. > >>> com/Non-UTF-8-string-encoding-support-in-BinaryMarshaller- > >>> IGNITE-5655-tp20024p20161.html > >>>> Sent from the Apache Ignite Developers mailing list archive at > >>> Nabble.com. > >>> > >> > >
