On Tue, Dec 29, 2015 at 7:15 PM, Pavel Stehule <pavel.steh...@gmail.com> wrote:
> >> I didn't check out earlier versions of this patch, but the latest one >> still changes pg_size_pretty() to emit PB suffix. >> >> I don't think it is worth it to throw a number of changes together like >> that. We should focus on adding pg_size_bytes() first and make it >> compatible with both pg_size_pretty() and existing GUC units: that is >> support suffixes up to TB and make sure they have the meaning of powers of >> 2^10, not 10^3. Re-using the table present in guc.c would be a plus. >> >> Next, we could think about adding handling of PB suffix on input and >> output, but I don't see a big problem if that is emitted as 1024TB or the >> user has to specify it as 1024TB in a GUC or argument to pg_size_bytes(): >> an minor inconvenience only. >> > > Last version still support BP in pg_size_pretty. It isn't big change. PB > isn't issue. > > We have to do significant decision - should to support SI units in > pg_size_bytes? We cannot to change it later. There is disagreement for SI > units in pg_size_pretty, so SI units in pg_size_bytes can be inconsistent. > There is no way at this point to add support for SI units in a consistent and backwards-compatible manner: both GUC and pg_size_pretty() use SI suffixes (kB, MB, GB, TB) with the meaning of 2^(10*n) (KiB, MiB, GiB, TiB). But given that the size relates to memory or disk space, it is quite customary *not* to use SI units, so I don't see a point in adding those. -- Alex
