On Fri, Jul 1, 2011 at 10:23 PM, Jens Alfke <[email protected]> wrote: > > On Jun 30, 2011, at 11:37 PM, Zdravko Gligic wrote: > >> But neither one even bothered trying to answer my question of whether >> just the last updated header or perhaps the last few are ever used. > > Just the last one. But at any point in time, the last one is vital for > recovery. It just becomes useless after another one is successfully appended.
Isn't that what I said? :) The evidence indicates "no." That's a shame. In my daily life I always worry about starting from an accidental advantage (speaking English), and assuming everybody else is advantaged, ultimately only causing confusion. In other words: Most Americans talk too fast, with too much slang. Anyway, to right my wrong and make it clear: The bottom rung of a ladder *was* important, when you stepped on it. Once at the top, we do not care about the bottom rungs. Similarly, the food you ate last year kept you alive, so it *was* very important. But today, last year's food is not relevant. With CouchDB (as others said), the last header is the important one; but once a new one is written, the old header is not relevant. (They might be *slightly* relevant in rare cases. For example, if your tape media was damaged and you have a partial backup; the old headers, now at the "end" of the truncated .couch file, are once again useful to access the older data. That situation however is very unlikely and/or completely contrived.) -- Iris Couch
