Re: Add parallelism and glibc dependent only options to reindexdb

On Mon, Jul 1, 2019 at 11:21 PM Peter Geoghegan <pg@bowt.ie> wrote:
>
> On Mon, Jul 1, 2019 at 1:34 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> > I have a vague recollection that ICU was providing some backward
> > compatibility so that even if you upgrade your lib you can still get
> > the sort order that was active when you built your indexes, though
> > maybe for a limited number of versions.
>
> That isn't built in. Another database system that uses ICU handles
> this by linking to multiple versions of ICU, each with its own UCA
> version and associated collations. I don't think that we want to go
> there, so it makes sense to make an upgrade that crosses ICU or glibc
> versions as painless as possible.
>
> Note that ICU does at least provide a standard way to use multiple
> versions at once; the symbol names have the ICU version baked in.
> You're actually calling the functions using the versioned symbol names
> without realizing it, because there is macro trickery involved.

Ah, thanks for the clarification!