Re: Sensible and NonsenSQL Aspects of the NoSQL Hoopla

Am Sonntag, 1. September 2013 19:49:48 UTC+2 schrieb Eric:

>
> In what way is the relational model insufficiently complete?
>

In my line of work the most frustating limit of the relational model is the omission of the order of tuples. Sorting part of SQL and not part of Codd's relational model. Even if sorting is entered through the back door it remains a tool to beautify the output and cannot be exploited while querying, since relations are unordered sets. Don't know if grouping and querying groups can be comprehend without reference to sorting order, since viewing and analyzing groups as a sorted list is easy to communicate and to implement. Hiding these algorithms behind "macro" functions like done in SQL is not the problem.

> Ordering and grouping are not part of the data definition, they are
> operations.

Grouping are part of the data definition:

employes are a set of (teachers, assistents, secretaries ...)

Every set with potential subsets can be defined with groups

m.f.G.

Karl Scheurer   Received on Mon Sep 02 2013 - 08:38:06 CEST