Vladimir, great suggestions. Can you please make an umbrella ticket with
sub-tasks, so we can tackle some of them for 2.1?
D.
On Mon, Apr 24, 2017 at 5:28 PM, Sergi Vladykin <sergi.vlady...@gmail.com>
wrote:
> Yes, we need to move on making Ignite work as any usual SQL db.
>
> But please avoid mixing all this stuff together, lets have a separate task
> (and discussion if needed) for each item in your list.
>
> Sergi
>
> 2017-04-24 16:58 GMT+03:00 Vladimir Ozerov <voze...@gridgain.com>:
>
> > Igniters,
> >
> > [long read, take a cup of coffee]
> >
> > Historically every SQL in Ignite must be executed against particular
> cache:
> > SqlQuery requires cache, JDBC and ODBC drivers require cache name. This
> > works fine until we add CREATE TABLE. Consider an empty cluster - how do
> > you connect to it if you have no caches yet? Nohow.
> >
> > It looks like we cannot have convenient access to cluster unless we
> > properly define and implement *schema* abstraction. ANSI SQL'92 defines
> > several abstractions: cluster -> catalog -> schema -> table/view/etc..
> > Every "catalog" has *INFORMATION_SCHEMA* schema, containing database
> > metadata. Almost all vendors support it (notable exclusion - Oracle).
> Looks
> > like we need to introduce similar concept and finally decouple caches
> from
> > schemas.
> >
> > High-level proposal from my side
> >
> > 1) Let's consider Ignite cluster as a single database ("catalog" in ANSI
> > SQL'92 terms).
> >
> > 2) It should be possible to connect to the cluster without a single user
> > cache. In this case schema is not defined.
> >
> > 3) We must have a kind of storage for metadata. It could be either
> another
> > system cache, or something analogous to binary metadata cache, which is
> > essentially node-local data structure exchanged on node join. It should
> be
> > aligned well with persistence feature, which is expected in AI 2.1.
> >
> > 4) Content of this storage will be accessible through INFORMATION_SCHEMA
> > abstraction.
> >
> > 5) We must support "CREATE SCHEMA", "DROP SCHEMA" commands which will
> > effectively create records in system cache and invoke relevant commands
> on
> > local H2 engines of every node (now it happens implicitly on cache
> > start/stop).
> >
> > 6) From JDBC/ODBC driver perspective schema will be defined either in
> > connection string, or in runtime through "SET SCHEMA" command which is
> > already supported by H2.
> >
> > 7) We must finally introduce new native SQL API, which will not use
> caches
> > directly. Something like "IgniteSql sql()". See *IGNITE-4701*.
> >
> > Once schema is there, usage of "CREATE TABLE" and "DROP TABLE" commands
> > will be simple and convenient, and it will fit naturally in user's past
> > experience with conventional RDBMS.
> >
> > Thoughts?
> >
> > P.S.: CREATE/DROP TABLE feature is not blocked by this problem. It will
> > work, but will be inconvenient for users.
> >
> > [1] https://issues.apache.org/jira/browse/IGNITE-4701
> >
>
