Re: SHOW TABLES - Mailing list pgsql-hackers

On Fri, 2010-07-16 at 20:52 +0300, Heikki Linnakangas wrote:
> On 16/07/10 20:11, Rob Wultsch wrote:
> > On Fri, Jul 16, 2010 at 9:56 AM, Robert Haas<robertmhaas@gmail.com>  wrote:
> >> For committers.
> >
> > Perhaps this discussions should be moved to the General list in order
> > to poll the userbase.
> >
> > My .02 is that SHOW commands (even if they are not compatible) would
> > make it much easier for me to make an argument to my boss to at least
> > consider moving off another open source database. The show commands
> > are in *very* widespread use by the MySQL community even after ~5
> > years of having the i_s. The Drizzle team (a radical fork of MySQL)
> > very briefly considered removing the SHOW commands and the unanimous
> > objections that followed caused that idea to scrapped.
> 
> That's for MySQL. I come from a DB2 background, and when I started using 
> psql years ago, I often typed "LIST TABLES" without thinking much about 
> it. Not SHOW TABLES, but LIST TABLES.

> I bet Oracle users coming to PostgreSQL will try "DESC". Not SHOW 
> TABLES. As Simon listed, every DBMS out there has a different syntax for 
> this.

Agreed

> I have nothing against SHOW TABLES 

...but SHOW wins, based on numbers of people expecting that

> (it might cause conflicts in grammar 
> though)

We don't have t handle it in the grammar. There are no parameters called
"tables", "databases" etc

> , but if we're going to cater to people migrating from MySQL, I 
> feel we should cater to people migrating from other products too. But 
> surely we're not going to implement 10 different syntaxes for the same 
> thing! We could, however, give a hint in the syntax error in all those 
> cases.

That's a very sensible suggestion, we should give a hint for all common
commands SHOW, LIST, etc., even though we pick just one to implement.

> That way we're not on the hook to maintain them forever, and we 
> will be 

> doing people a favor by introducing them to the backslash 
> commands

That's a sentence I never thought to see written down

> or information schema, which are more powerful.

and this in no way detracts from that power and standardisation.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Training and Services