Development plan changes for Rails 5.2 and 6.0

[Yasuo Honda]

Hi,

I am in Hiroshima city to attend RubyKaigi 2017. 

Today I'd like to announce Oracle enhanced adapter "nextval" plan has been cancelled.

Since "Next versions of Oracle enhanced adapter 1.9 and "nextval" 2.0 for Rails 5.2" announced(refer *1), 

there have been some commits made at "nextval" branch.  

However, using `identity` datatype to replace sequence based primary key is much more complicated than I expected 

it is mainly due to missing `insert ... default values` support in Oracle Database 12.2.  (refer *2 and *3)

Here are new plans for Rails 5.2 and 6.0 after lessons learned developing "nextval" branch.

### Plans for Rails 5.2

- There will be no more commits at "nextval" branch

It will be kept for some time until cherry-picking changes into current master branch.

- Next version of Oracle enhanced adapter to support Rails 5.2 is also 5.2, not 1.9.

### Current plans for Rails 6.0

* Only supports Oracle Database 11.2 (aka 11gR2) or higher

11.1 (11gR1) or lower version will not be supported. 

* Database link support will be dropped in 6.0

* Trigger based primary key support will be droped in 6.0.

### References

*1 "Next versions of Oracle enhanced adapter 1.9 and "nextval" 2.0 for Rails 5.2"

https://groups.google.com/forum/#!topic/oracle-enhanced/dN6WSwprAnY

*2 The latest commit at "nextval" branch to handle Oracle internal sequence objects:

https://github.com/rsim/oracle-enhanced/pull/1483

*3 Add support for INSERT .. DEFAULT VALUES

https://community.oracle.com/ideas/13845

Thanks,

--

Yasuo Honda