Re: pg_trgm comparison bug on cross-architecture replication due to different char implementation

On Thu, Sep 12, 2024 at 03:42:48PM -0700, Masahiko Sawada wrote:
> On Tue, Sep 10, 2024 at 3:05 PM Noah Misch <noah@leadboat.com> wrote:
> > On Tue, Sep 10, 2024 at 05:56:47PM -0400, Tom Lane wrote:
> > > Got it.  So now I'm wondering if we need all the complexity of storing
> > > stuff in the GIN metapages.  Could we simply read the (primary's)
> > > signedness out of pg_control and use that?

> I've attached a PoC patch for this idea. We write  the default char
> signedness to the control file at initdb time. Then when comparing two
> trgms, pg_trgm opclasses use a comparison function based on the char
> signedness of the cluster. I've confirmed that the patch fixes the
> reported case at least.

I agree that proves the concept.