Re: head fails to build on SLES 12 (wal_compression=zstd)

Justin Pryzby <pryzby@telsasoft.com> writes:
> Possible responses look like:
>  - Use 0 which also means "default" (need to verify that works across versions);
>  - Or #ifndef ZSTD_CLEVEL_DEFAULT #define ZSTD_CLEVEL_DEFAULT 3;
>  - Add a test for a minimum zstd version v1.3.7.  This may be a good idea for
>    v15 in any case, since we're using a few different APIs (at least
>    ZSTD_compress and ZSTD_compressStream2 and execve(zstd)).

In view of 51c0d186d ("Allow parallel zstd compression"), I agree
that some clarity about the minimum supported version of zstd
seems essential.  I don't want to be dealing with threading bugs
in ancient zstd versions.  However, why do you suggest 1.3.7 in
particular?

            regards, tom lane