Re: POSTGRES/MYSQL

On 12/03/2019 09:40, Thiemo Kellner wrote:
>
> Quoting Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>:
>
>> On 3/11/19 9:31 AM, Sonam Sharma wrote:
>>> Hi Adrian,
>>> Ours is retail company and the DB size is Max 30gb, currently we are
>>> using db2.
>>
>> Things to consider:
>>
>> 1) Migration tools for DB2 --> MySQL/Postgresql. I have not done
>> this, so someone else will have to comment.
>>
>> 2) The clients/frameworks/ORMs you use now to connect to the
>> database. Do they also work with Postgresql/MySQL?
>
> It is also worth to consider if the architecture/model of DB2 fits
> PostgreSQL/MySQL. And while at it, how about getting rid of all the
> itching quirks of the current solution anyway? I see the danger of
> getting disappointed by any of PostgreSQL/MySQL if the current
> solution uses DB2 features that cannot be easily mapped to any of the
> contenders features.
>
> Bottom line of my insinuation is that the migration tool could be less
> an point if you get the opportunity to overhaul your application.
>
> Kind two dimes
>
> Thiemo
>
>
Yes, I'm aware that different RDDBMS's having their own quirks that
people either exploit as benefits, or have to work around in a new DB. 
So naively converting one DB to another may have huge performance hits,
and possible unexpected results (MySQL, I'm looking at you!) -- even if
both DB's were technically equally good!

I think a conversion tool is a good starting point.  However, I strongly
agree with Thiemo, that you should carefully review your existing
databases design/implementation -- so as to take maximum advantage of
the facilities of progress, and avoid any pitfalls created by naively
importing isms that are specific to your old db -- that might well be
counter productive in PostgreSQL.

Cheers,
Gavin