[tz] Rules for TZ+ database

[Brian Inglis]

On 2013-09-05 08:52, Paul Eggert wrote:

> Yes, visibility is a problem, but it's not the only problem.
> We also have data bloat even if the set of identifiers
> remains the same, because turning a link into a zone
> has a runtime expense.

Build time and ~4KB file storage expense, no runtime difference, other than the 
overhead of accessing via a link (on distros which support links, and use them).

The storage overhead is negligible for most as host distros provide both posix 
and right alternatives.

For perspective, total source data is <800KB, binary data <800KB for POSIX, 
<1100KB for right.