Not recommended to use server-side functions in MongoDB, does this go for MapReduce as well?

Question

The MongoDB documentation states that it is not recommended to use its stored functions feature. This question goes through some of the reasons, but they all seem to boil down to "eval is evil".

Are there specific reasons why server-side functions should not be used in a MapReduce query?

Map redue is a vital part of progressive back end aggregation, so no it does notapply, as to using them in MR, it is OK too — Sammaye, Sep 17 '13 at 14:54

score 0 · Answer 1 · answered Sep 17 '13 at 14:59

The system.js functions are available to Map Reduce jobs by default ( https://jira.mongodb.org/browse/SERVER-8632 notes a slight glitch to that in 2.4.0rc ).

They are not actually evaled within the native V8/Spidermonkey evironment so tehcnically that part of them is also gone.

So no, there is no real problems, they will run as though native within that Map Reduce and should run just as fast and "good" as any other javascript you write. In fact the system.js collection is more designed to house code for map reduce jobs, it is later uses that sees it used as a hack for "stored procedures".

Not recommended to use server-side functions in MongoDB, does this go for MapReduce as well?

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