Postgres and other database interfaces

[Denis F]

On Saturday, 24 February 2018 at 05:45:45 UTC, rikki cattermole 
wrote:
> There is plenty of desire to build a generalized SQL interface 
> for Phobos.
>
> But somebody needs to do it and it won't be all that much fun 
> to do.

I want to dwell on this.

It seems to me that this is a common misconception that it is 
possible to create a good universal tool for accessing the 
database in place of the many existing ones.

SQL is something like BASIC from the 70-80s: there is no single 
standard, there are many dialects. And the differences are both 
syntactic and deep, for example, Postgres and Oracle differently 
interpret the ANSI standard concerning transactions. The same 
applies to the connection layer: some of the databases allow you 
to organize a gradual download of the results, some - feedback in 
the form of something like "events", etc. Also, Postgres 
quarantiees that result of query will be immutable and this is 
very useful, but some one another DB maybe not.

At best, such a tool will be suitable for simple trivial things.

On the other hand, needing  for this is also not obvious - 
databases in real projects isn't switched usually every 
week/month because they are not interchangeable, except for some 
very simple cases. Usually RDBMS engine should be elected based 
on your requiriments before you start to use it.