Re: Aggregation (with GBY) is Relational Division

From: Mikito Harakiri <mikharakiri_nospaum_at_yahoo.com>
Date: 5 Jun 2006 12:18:30 -0700
Message-ID: <1149535110.158646.31870_at_c74g2000cwc.googlegroups.com>


vadimtro_at_gmail.com wrote:
> Bag# Pos# Val sum min max
> ---- ---- --- --- --- ---
> 0 0 0 0 0 0
> 1 0 1 1 1 1
> 2 0 2 2 2 2
> 3 0 3 3 3 3
> ....
> 4 0 0 0 0 0
> 4 1 0 0 0 0
> 5 0 0 1 0 1
> 5 1 1 1 0 1
> 6 0 1 1 0 1
> 6 1 0 1 0 1
> 7 0 2 2 0 2
> 7 1 0 2 0 2
> 8 0 1 2 0 1
> 8 1 1 2 0 1
> ....
> 9 0 0 0 0 0
> 9 1 0 0 0 0
> 9 2 0 0 0 0
> ....

Comments:
1. Relation would be "much bigger" (but still countable) if all the rational values are enumerated.
2. What is a practical method to perform set join between infinite relation Aggr and Dept?
2. The max column is redundant, see the postulate.

Postulate. There are only two fundamental aggregates: sum, and min. All the other aggregates reduce to the above. Received on Mon Jun 05 2006 - 21:18:30 CEST

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