Re: MySQL-ism help patch for psql - Mailing list pgsql-hackers

On Jan 19, 2010, at 2:58 PM, Stefan Kaltenbrunner wrote:

> Tom Lane wrote:
>> Jeff Davis <pgsql@j-davis.com> writes:
>>> That being said, I don't have much of an opinion, so if you see a
>>> problem, then we can forget it. After all, we would need some kind  
>>> of a
>>> prefix anyway to avoid conflicting with actual SQL... maybe "\m"?  
>>> And
>>> that defeats a lot of the purpose.
>> Yeah, requiring a prefix would make it completely pointless I think.
>> The submitted patch tries to avoid that by only matching syntax  
>> that's
>> invalid in Postgres, but that certainly limits how far we can go with
>> it.  (And like you, I'm a bit worried about the LOAD case.)
>
> yeah requiring a prefix would make it completely pointless

Agreed.

>> The last go-round on this was just a couple months ago:
>> http://archives.postgresql.org/pgsql-bugs/2009-11/msg00241.php
>> although I guess that was aimed at a slightly different idea,
>> namely making "show databases" etc actually *work*.  This one at
>> least has a level of complication that's more in keeping with the
>> possible gain.
>
> well providing a hint that one should use different command will  
> only lead to the path "uhm why not make it work as well" - and we  
> also need to recongnized that our replacements for some of those  
> commands are not really equivalent in most cases.

I think if you set this line ahead of time, you don't have to worry  
about the detractors; this is equivalent to vim outputting  
"Type  :quit<Enter>  to exit Vim" when you type emacs' quit sequence.   
The intent is to show the correct way or to provide a helpful reminder  
to people new to psql, not to make it work the same.

>> The previous discussion started from the idea that only DESCRIBE,
>> SHOW DATABASES/TABLES, and USE were worth worrying about.  If we
>> were to agree that we'd go that far and no farther, the potential
>> conflict with SQL syntax would be pretty limited.  I have little
>> enough experience with mysql to not want to opine too much on how
>> useful that would be, but it does seem like those are commands
>> I use right away anytime I am using mysql.
>
> well those are the most common ones I guess for the current version  
> of the mysql commandline client - but what about future versions or  
> the fact that we only have partial replacements for some of those  
> that people are really asking for?

I think it captures the intent of the people using the tool, and that  
it adds a small net benefit in usability for those people.  Deciding  
to support this small subset does not obligate you to expand the scope  
in the future.  (Hey ma, this slope ain't slippery!)

Regards,

David
--
David Christensen
End Point Corporation
david@endpoint.com