Re: specific query (not all) on Pg8 MUCH slower than Pg7

On 5/8/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> You're not getting the indexscan optimization of the LIKE clause, which
> is most likely due to having initdb'd the 8.1 installation in something
> other than C locale.  You can either redo the initdb in C locale (which
> might be a good move to fix other inconsistencies from the 7.3 behavior
> you're used to) or create a varchar_pattern_ops index on the column(s)
> you're using LIKE with.

Given the performance implications of setting the wrong locale, and
the high probability of accidentally doing this (I run my shells with
LANG=en_US.UTF-8, so all my databases have inherited this locale), why
is there no support for changing the database locale after the fact?

# alter database test set lc_collate = 'C';
ERROR:  parameter "lc_collate" cannot be changed

Alexander.