Re: CHAR vs NVARCHAR vs TEXT performance

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> > On Tue, Apr 30, 2019 at 5:44 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> FWIW, my recommendation for this sort of thing is almost always
> >> to not use CHAR(n). The use-case for that datatype pretty much
> >> disappeared with the last IBM Model 029 card punch.
> ...
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Perhaps the "tip" on the character datatype page (
https://www.postgresql.org/docs/11/datatype-character.html) should be
updated as the statement "There is no performance difference among these
three types..." could easily lead a reader down the wrong path. The
statement may be true if one assumes the planner is able to make an optimal
choice but clearly there are cases that prevent that. If the situation is
better explained elsewhere in the documentation then just a link to that
explanation may be all that is needed.

Cheers,
Steve