Re: [HACKERS] Re: [QUESTIONS] is Postgres an SQL-based database?

> I agree with you Tom, PostgreSQL should be more than standard,
> but users expect that PostgreSQL at least supports SQL syntax.
> I agree with you if you talk about implement functions not supported by SQL
> but I can't understand if you write the same function with another syntax.

Well, one explanation is that sometimes I get it wrong :)

> PostgreSQL has many functions that doesn't follow SQL-standard syntax.
> I can understand this:
>
> ROLLBACK [ WORK ] -- SQL-syntax
> rollback [transaction|work] -- PostgreSQL-syntax (this is more than standard)
>
> and
>
> ALTER TABLE <class_name> ADD [COLUMN] <attr> <type>; --SQL
> alter table <class_name> [*] add column <attr> <type>; --PostgreSQL
>
> In this case [*] show that PostgreSQL is an ORDBMS,
> but what about keyword COLUMN? It sould be optional.
>
> but I can't understand things like:
>
> \connect <dbname|-> <user> --PostgreSQL
> insted of:
> CONNECT TO { DEFAULT | <SQL-server name> --SQL
> [ AS <connection name> ]
> [ USER <user name> ] }

Connections are done by the frontend, which does not parse the SQL. We could think about
implementing this if we allowed the backend to force a database change. Don't know if
this is easy or reasonably so.

> CAST expression AS data-type --PostgreSQL
> insted of:
> CAST ( expression AS { data-type | domain } ) --SQL

Wow, I never noticed that parens are in the syntax! Will look at changing it...

- Tom