Correct, it worked, because Ignite has never had real database use case in mind. Unfortunately, if our global plans go as expected, it will not work for Ignite 2.x+.
On Fri, Jan 13, 2017 at 11:53 AM, Sergi Vladykin <sergi.vlady...@gmail.com> wrote: > Lets move on with SQL schema == Ignite cache. It worked always like this, I > see no reasons to change this. > > Sergi > > 2017-01-13 11:20 GMT+03:00 Vladimir Ozerov <voze...@gridgain.com>: > > > "Tablespace" (Oracle, PostgreSQL) is what maps better than "schema" to > our > > cache. But not ideally still. > > > > On Fri, Jan 13, 2017 at 11:10 AM, Vladimir Ozerov <voze...@gridgain.com> > > wrote: > > > > > Alex, > > > > > > Currently Ignite is not used as database. It is used as search engine - > > > several types, several tables, several joins. This is why having > "SCHEMA > > == > > > cache" was never a problem. Users have never build complex SQL > > applications > > > on top of Ignite. But we are going towards database. And my question > > stands > > > still - suppose it is Y2019, how is user going to migrate his database > > > containing 20-30-50-100 tables in a single schema in Oracle to Ignite? > > > > > > Single cache for all tables? Doens't work - not flexible. Users will > > > definitely require different cache modes, different co-location rules, > > > different number of backups, etc.. > > > Schema per table? Doesn't work either - unmanageable and not convenient > > > for users even for relatively small databases. > > > > > > From user perspective schema is logical grouping of database objects, > > > nothing more. > > > > > > For Ignite schema could be a logical group of resources (nodes, memory > > > pools, caches, etc.). And multiple tables over multiple caches should > > > reside in it. To the contrast, table definition governs how data is > > stored. > > > This is similar to, for example, MySQL approach, where you define how > you > > > store data on per-table level, and on schema level you define only > minor > > > things like collation. > > > > > > Vladimir. > > > > > > > > > On Fri, Jan 13, 2017 at 10:33 AM, Alexander Paschenko < > > > alexander.a.pasche...@gmail.com> wrote: > > > > > >> Vova, > > >> > > >> 2017-01-13 4:56 GMT+08:00 Vladimir Ozerov <voze...@gridgain.com>: > > >> > I am not quite sure I understand the idea of "SCHEMA == cache". > > Consider > > >> > some small database with, say, ~30 tables. And user wants to migrate > > to > > >> > Ignite. How is he supposed to do so? 30 schemas leading to rewrite > of > > >> all > > >> > his SQL scripts? Or 30 key-value pairs in a single cache leading to > > >> lack of > > >> > flexibility and performance problems? > > >> > > >> But currently schema *is* semantically equal to cache while table is > > >> equal to type descriptor (i.e. type of stored entities), nothing new > > >> here. > > >> > > >> Say, in single cache we may have entities of types Person and > > >> Organization, those map to two tables with same names, and can be > > >> accessed within the same cache (i.e. schema). > > >> > > >> If we want to limit the user with having single type descriptor per > > >> cache (i.e. cache has only one type of stored entities - BTW, where we > > >> are with this 2.0-wise?), then this notion could change. But currently > > >> what has been suggested already fits quite good with what we do have > > >> at the moment regarding semantic of SQL objects. > > >> > > >> - Alex > > >> > > >> > Another example is how to deal with referene tables? Lots database > has > > >> > small reference tables which is best to fit REPLICATED cache, while > > >> others > > >> > are usually bound to PARTITIONED mode. "SCHEMA == cache" will force > > >> users > > >> > to split them into separate schemes leading to poor user experience. > > >> > > > >> > I understand that we may have some implementation details around it > at > > >> the > > >> > moment. But from user perspective "SCHEMA == cache" doesn't make > > sense. > > >> As > > >> > we are going towards AI 2.0 we'd better to rethink this approach. > > >> > > > >> > On Thu, Jan 12, 2017 at 11:46 PM, Denis Magda <dma...@apache.org> > > >> wrote: > > >> > > > >> >> > > >> >> > On Jan 12, 2017, at 12:35 PM, Dmitriy Setrakyan < > > >> dsetrak...@apache.org> > > >> >> wrote: > > >> >> > > > >> >> > On Thu, Jan 12, 2017 at 9:47 AM, Sergi Vladykin < > > >> >> sergi.vlady...@gmail.com> > > >> >> > wrote: > > >> >> > > > >> >> >> The xml config was only for example. We can put in this > > >> configuration > > >> >> >> string cache config parameters directly like this: > > >> >> >> > > >> >> >> CREATE SCHEMA "MyCacheName" WITH > > >> >> >> "cacheMode=REPLICATED;atomicityMode=ATOMIC" > > >> >> >> > > >> >> > > > >> >> > This approach makes sense, if it can be easily supported with H2. > > >> >> > > >> >> What’s for affinity keys? Can we make an exception for them by > > >> defining in > > >> >> this part of the statement > > >> >> > > >> >> CREATE TABLE employee ( > > >> >> id BIGINT PRIMARY KEY, > > >> >> dept_id BIGINT AFFINITY KEY, > > >> >> name VARCHAR(128), > > >> >> ); > > >> >> > > >> >> or that l > > >> >> > > >> >> CREATE TABLE employee ( > > >> >> id BIGINT PRIMARY KEY, > > >> >> dept_id BIGINT, > > >> >> name VARCHAR(128), > > >> >> CONSTRAINT affKey AFFINITY KEY(dept_id) > > >> >> ); > > >> >> > > >> >> ? > > >> >> > > >> >> — > > >> >> Denis > > >> >> > > >> >> > > >> > > > > > > > > >
