maria-developers team mailing list archive

[Alexander Barkov <bar@xxxxxxxxxxx>]

Hello Jerome,

On 01/26/2017 11:35 PM, jerome brauge wrote:
> Hi,
> I'm testing datatype compatibility provide by MDEV-10343 and I have some comments:
> 1) Oracle character datatype (char, varchar, varchar2) doesn't accept a length of 0 char
> Example :
> 	select cast('tt' as char(0)) from dual;
> 	ORA-01723: zero-length columns are not allowed
> MariaDB return an empty string (to relate with MDEV-10574)
> This point is a study case, no matter.
> 
> 2) NUMBER Type
> You have choosing TYPE_DOUBLE if scale/prec is not specified and I think that it's a mistake for 2 reasons:
> - Oracle NUMBER() is near an "exact" datatype and cannot be replace by a standard double.
> - Convert number to char never use scientific notation 
> 
> The use of a decimal(64,24) makes it possible to obtain results very close to those of oracle.
> I attach two files to show this.
> 
> In fact FLOAT and INTEGER are  subtype of NUMBER for Oracle.
> MariaDB float and double seems to be like BINARY_FLOAT and BINARY_DOUBLE.
> 
> See https://docs.oracle.com/cd/B28359_01/server.111/b28285/sqlqr06.htm#CHDBBHHE for more details.

Thanks for a good proposal. I have created a task for this:

https://jira.mariadb.org/browse/MDEV-11921

> 
> Best regard,
> Jérôme.
> 
>