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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