BUG #16835: btree index does not work for where clause using 'foo%'

The following bug has been logged on the website:

Bug reference:      16835
Logged by:          Hongyan (Heather) Zhang
Email address:      [hidden email]
PostgreSQL version: 11.9
Operating system:   aurora postgres 11
Description:        

https://www.postgresql.org/docs/11/indexes-types.html, according to this
page, btree index is supposed to work for where clause col like 'foo%', but
does not work for me. we are on aurora postgres 11, I also tested on
postgres 11, it does not work either.

PG Bug reporting form <[hidden email]> writes:
> https://www.postgresql.org/docs/11/indexes-types.html, according to this
> page, btree index is supposed to work for where clause col like 'foo%', but
> does not work for me. we are on aurora postgres 11, I also tested on
> postgres 11, it does not work either.

As the manual explains, that will not work by default unless your
database locale is C (which is an uncommon default nowadays).

It's also possible that Aurora has changed something that keeps
it from working, but I'd investigate the locale angle first.

                        regards, tom lane

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