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https://issues.apache.org/jira/browse/COUCHDB-796?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12878321#action_12878321
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Adam Kocoloski commented on COUCHDB-796:
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>From dev@
On Jun 12, 2010, at 3:33 PM, Jason Smith wrote:
> I hate to sidetrack conversation but I am unclear which Couch component has a
> bug.
No problem, it's good that people understand this. There are two bugs. Bug #1
is that roundtrip encoding/decoding of big numbers in the Erlang VM is not
supported:
1> Original = <<"[12345678911234567892123456789312345678941234567895]">>.
<<"[12345678911234567892123456789312345678941234567895]">>
2> RoundTrip = couch_util:json_encode(couch_util:json_decode(Original)).
[91,"1.2345678911234567e+49",93]
3> io:format("~s~n", [RoundTrip]).
[1.2345678911234567e+49]
Anything larger than a 32 bit integer is cast to a float. This is trivial to
fix, and in fact the behavior is a regression since 0.10.x, when we were
running a forked mochijson2.
Bug #2 is that the Javascript VM represents Numbers as double precision
floating-point, so anything with more than 15 digits of precision gets rounded
off. I imagine your bigdecimal.js, but it would need the numbers as strings,
right? Hence Bob's original suggestion
> Bignum support
> --------------
>
> Key: COUCHDB-796
> URL: https://issues.apache.org/jira/browse/COUCHDB-796
> Project: CouchDB
> Issue Type: Improvement
> Components: Database Core
> Affects Versions: 0.11
> Reporter: Robert Newson
> Fix For: 1.0
>
>
> CouchDB uses spidermonkey which can only handle 32 bit integer values before
> overflowing. This might surprise users of map/reduce on large datasets.
> Instead, alter mochijson2.erl to handle bignums and encode numeric values as
> strings.
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