Re: Mixed Locales and Upgrading

On Tue, Mar 17, 2020 at 10:45:50AM -0400, Tom Lane wrote:
> Don Seiler <don(at)seiler(dot)us> writes:
>> What are the ramifications of changing collation like that? Should we
>> consider rebuilding indexes ASAP after that?
>
> Text indexes would definitely be at risk here. I'm not really certain
> how bad the problem would be. Do you have a feeling for how much of
> the data is 100% ASCII? If you could be sure of that for any given
> column, you wouldn't have to reindex indexes on that column.

There is no way to know how much indexes would get broken without
having a look at it. Anything ASCII-based should be of no problem.
If you have a doubt, reindexing evey index which includes text column
data is the best course of action in my opinion if you have any
doubts, because that's safe even if it has a higher cost.
--
Michael