Re: pgsql: doc: add examples of creative use of unique expression indexes

On Fri, Apr 10, 2020 at 07:21:29PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > I agree with your analysis. I still want to have some mention that
> > partial indexes can be used to create single-NULL columns, which might
> > be required for compatibility with other databases. Attached is an
> > updated patch which removes the previous commit but adds a mention of
> > this.
>
> The single-null thing is probably a useful example, but please make
> it an actual separate example, or at least its own para outside the
> existing <example> sections.
>
> Also, the existing example demonstrating that seems overcomplicated;
> why not just
>
> create unique index ... (1) where (foo is null);

I ended up using "true" since that is ony one byte; patch attached.

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Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EnterpriseDB https://enterprisedb.com

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