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From Alexander Paschenko <alexander.a.pasche...@gmail.com>
Subject Re: DDL implementation details
Date Thu, 12 Jan 2017 17:21:37 GMT
Sergi, Alexey G.,

I see your point and am rather inclined to agree that we should let
current notion of "single schema - multiple tables" live.

Still, if we create schema with cache config file, what's the whole
point of SQL then if the user anyway has to write XML? This probably
could be useful to propagate configuration to all cluster nodes tho.

And if we skip CREATE TABLE now, it means that we leave user facing
the need to write XML configuration, no other options. Is this what we
want?

Still I must admit that leaving user with his familiar XML stuff looks
attractive - no messing with bunch of unknown new params, just write
your XML and go. Also it's portable and allows to re-use
configurations easily, so undoubtedly is a good approach from some
point.

- Alex

2017-01-12 23:51 GMT+08:00 Sergi Vladykin <sergi.vladykin@gmail.com>:
> Hi,
>
> 1. For now I'm against inventing any custom SQL syntax and implementing
> parsing.
> Currently H2 supports the following syntax:
>
> CREATE TABLE test(...) WITH "myCustomParamString"
>
> This is enough for us to pass the needed parameters.
>
> 2. Agree with AG, we have to separate cache creation from table creation.
> Cache == SQL schema for us. We just have to add the same WITH syntax in H2
> for schema creation like this:
>
> CREATE SCHEMA "MyCacheName" WITH "cacheConfig=myCache.xml"
>
> 3. If we want to create tables then I suggest to put this functionality to
> 2.0+PageMemory right away and think where and how we are going to store all
> the related metadata.This is especially important for persistent storages.
>
> Sergi
>
>
> 2017-01-12 16:56 GMT+03:00 Vladimir Ozerov <vozerov@gridgain.com>:
>
>> I am afraid in this case user will have to define too much schemes -
>> boilerplate.
>> Does it make sense at all to pack multiple tuples into a single cache from
>> user perspective?
>>
>> On Thu, Jan 12, 2017 at 4:40 PM, Alexey Goncharuk <
>> alexey.goncharuk@gmail.com> wrote:
>>
>> > Alexander,
>> >
>> > Will we keep the old option to have multiple tables in one cache? If so,
>> > how will create table statement know which cache to choose?
>> >
>> > It seems to me that to be consistent with the current DML implementation
>> we
>> > should have a CREATE SCHEMA statement which will define the cache and
>> cache
>> > configuration, and CREATE TABLE should specify the schema name.
>> >
>> > Otherwise, we should enforce the single type per cache rule at the
>> > configuration level and in runtime.
>> >
>> > As for affinity and primary key - agree with Vladimir.
>> >
>> > --
>> > AG
>> >
>> > 2017-01-12 11:41 GMT+03:00 Sergey Kozlov <skozlov@gridgain.com>:
>> >
>> > > As first stage of DDL we can implement following CREATE TABLE statement
>> > > support:
>> > >  - CREATE TABLE without cache properties (use default cache properties
>> or
>> > > cache properties defined in SQL Schema)
>> > >  - CREATE TABLE .. LIKE where we can create a cache based on an another
>> > > existing cache.
>> > >
>> > > On Thu, Jan 12, 2017 at 5:54 AM, Dmitriy Setrakyan <
>> > dsetrakyan@apache.org>
>> > > wrote:
>> > >
>> > > > Agree with Sergey. We should be able to specify cache properties
>> inside
>> > > of
>> > > > SQL statements. Does H2 have any support to process SQL hints? Can
we
>> > > > change it?
>> > > >
>> > > > Having said that, while we finalize the above, I think we should
>> start
>> > > > working on DDL implementation to use the default settings, as
>> specified
>> > > in
>> > > > Alexander's email.
>> > > >
>> > > > Also agree with the stop-the-world on the cache for index creation.
>> We
>> > > can
>> > > > always improve on it in future.
>> > > >
>> > > > D.
>> > > >
>> > > > On Wed, Jan 11, 2017 at 11:28 AM, Sergey Kozlov <
>> skozlov@gridgain.com>
>> > > > wrote:
>> > > >
>> > > > > Hi
>> > > > >
>> > > > > I suppose we should put any ignite cache properties as additional
>> > > > > non-standard attributes after CREATE TABLE () clause as it does
>> > > > Postgress,
>> > > > > MySQL and other RDBMS.
>> > > > > Take a look on CREATE TABLE with using TABLESPACE (Postgess)
or for
>> > > > CREATE
>> > > > > TABLE with using PARTITIONS (MySQL).
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > > On Wed, Jan 11, 2017 at 10:05 PM, Vladimir Ozerov <
>> > > vozerov@gridgain.com>
>> > > > > wrote:
>> > > > >
>> > > > > > I believe custom synthax and parsing is a *must* for us,
as well
>> as
>> > > for
>> > > > > any
>> > > > > > distributed database. At the very least we need to specify
>> affinity
>> > > key
>> > > > > > column somehow. Any cache property can be specified at the
very
>> end
>> > > of
>> > > > > > table definition. Key columns can be determined as the ones
with
>> > > > PRIMARY
>> > > > > > KEY constraint (Alex K. idea) + affinity column(s):
>> > > > > >
>> > > > > > CREATE TABLE employee (
>> > > > > >     id BIGINT PRIMARY KEY,
>> > > > > >     dept_id BIGINT AFFINITY KEY,
>> > > > > >     name VARCHAR(128),
>> > > > > >     address VARCHAR(256)
>> > > > > >     BACKUPS 2,
>> > > > > >     ATOMICITY_MODE ATOMIC,
>> > > > > > );
>> > > > > >
>> > > > > > "id" and "dept_id" form key type, "name" and "address" form
value
>> > > type.
>> > > > > >
>> > > > > > Vladimir.
>> > > > > >
>> > > > > > On Wed, Jan 11, 2017 at 9:08 PM, Alexey Kuznetsov <
>> > > > akuznetsov@apache.org
>> > > > > >
>> > > > > > wrote:
>> > > > > >
>> > > > > > > Hi, Alex!
>> > > > > > >
>> > > > > > > As far as I know most RDBMS allow something like: create
table
>> t1
>> > > (id
>> > > > > > > integer primary key, ....)
>> > > > > > > How about to take as key field that marked as "primary
key"?
>> > > > > > >
>> > > > > > > As of atomicity and replication - I think it is a cache
>> > properties
>> > > > and
>> > > > > > with
>> > > > > > > create table we will create "types" in cache. No?
>> > > > > > > I thought that cache it is a kind of "schema" in RDBMS.
>> > > > > > >
>> > > > > > > Could you describe what will be created with CREATE
TABLE?
>> > > > > > >
>> > > > > > > On Thu, Jan 12, 2017 at 12:54 AM, Alexander Paschenko
<
>> > > > > > > alexander.a.paschenko@gmail.com> wrote:
>> > > > > > >
>> > > > > > > > Hello Igniters,
>> > > > > > > >
>> > > > > > > > I would like to start discussion about implementation
of SQL
>> > DDL
>> > > > > > > commands.
>> > > > > > > >
>> > > > > > > > At the first stage, the most important ones seem
to be CREATE
>> > > TABLE
>> > > > > > > > (that will obviously correspond to creation of
a cache) and
>> > > CREATE
>> > > > > > > > INDEX.
>> > > > > > > >
>> > > > > > > > Regarding first one: SQL command for CREATE TABLE
does not
>> > > contain
>> > > > > any
>> > > > > > > > hints about cache settings (atomicity, replication,
etc.), so
>> > > these
>> > > > > > > > will probably be defined by some configuration
properties
>> (like
>> > > > > > > > ignite.ddl.default_cache_atomiticity, etc).
>> > > > > > > >
>> > > > > > > > Also it does not allow to distinguish between
key and value
>> > > > columns -
>> > > > > > > > currently it is handled by keyFields property
of QueryEntity,
>> > but
>> > > > it
>> > > > > > > > is unclear how to declare key fields via CREATE
TABLE.
>> > > > > > > >
>> > > > > > > > So at a first glance it seems like we should either
implement
>> > > some
>> > > > > > > > sort of custom parsing (I believe Sergi will be
against it)
>> or
>> > > > > > > > introduce some kind of name prefix that would
tell SQL engine
>> > > that
>> > > > > > > > certain column is a key field column.
>> > > > > > > >
>> > > > > > > > Of course, this problem disappears is key is of
SQL type.
>> > > > > > > >
>> > > > > > > > Regarding CREATE INDEX: probably at first we will
have to
>> > > implement
>> > > > > > > > this in "stop-the-world" manner, i.e. all cache
will be
>> blocked
>> > > > > during
>> > > > > > > > the index's initial buildup.
>> > > > > > > >
>> > > > > > > > Any thoughts?
>> > > > > > > >
>> > > > > > > > Currently I'm working on parsing of those commands
as that
>> will
>> > > be
>> > > > > > > > needed anyway and does not affect further implementation.
>> > > > > > > >
>> > > > > > > > - Alex
>> > > > > > > >
>> > > > > > >
>> > > > > > >
>> > > > > > >
>> > > > > > > --
>> > > > > > > Alexey Kuznetsov
>> > > > > > >
>> > > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > > --
>> > > > > Sergey Kozlov
>> > > > > GridGain Systems
>> > > > > www.gridgain.com
>> > > > >
>> > > >
>> > >
>> > >
>> > >
>> > > --
>> > > Sergey Kozlov
>> > > GridGain Systems
>> > > www.gridgain.com
>> > >
>> >
>>

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