Re: Getting a sample data set.

On Tue, January 18, 2011 13:23, Alban Hertroys wrote:
>
>
> Standard SQL alternatives tend to get complex, using self-joins to
> weed out all the records you don't want (the exact term for such
> joins escapes me right now, that would help with Googling if you're
> looking for examples).

Would the term be a grouped self join?

> Basically you do something like:
> SELECT s1.mode
>   FROM shipments AS s1
>  WHERE NOT EXISTS (
>     SELECT NULL
>       FROM shipments AS s2
>      WHERE s1.mode = s2.mode
>        AND s1.somecolumn < s2.somecolumn
>     )
>


I can see the motivation for something like DISTINCT ON.  I take it
that this syntax is peculiar to PostgreSQL?:


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