[Cubicweb] unique constraint on unlimited String attribute

Florent Cayré florent.cayre at logilab.fr
Fri Jun 17 12:08:08 CEST 2016


On 06/16/16 15:03, Julien Cristau wrote:
> I guess one option is to have an extra computed column with a (fixed
> size) hash of your nvarchar(max) column, and index *that*, but
> reconsidering either the index or the lack of size limit might be
> better.

Agreed for search (indexed=True in yams), not for uniqueness
(unique=True in yams).

This suggestion would also make it possible to handle cwuri's example
properly (using a limited-in-length but reversed string for the indexed
column for instance). There should be litterature around for this topic.

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