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From Jens Alfke <>
Subject Re: Ad-hoc filtering
Date Tue, 26 Feb 2013 20:34:30 GMT

On Feb 26, 2013, at 12:19 PM, Daniel Gonzalez <<>>

Just curious: is there a major technical reason not to have that capability
integrated in couchdb, or is just a matter of separation of
responsibilities and specialization?

The latter, I think. CouchDB is lower-level than that. Its views are the types of indexes
that, say, a SQL database would generate, but view queries are pretty limited to doing the
types of queries you can natively do on a pre-existing index, like subranges and grouping.

The kind of more complex queries you want require an engine that’s built on top of that,
which can plan out what indexes are needed for a query, generate them if necessary, extract
data from one or more indexes, and then merge/collate/transform it. In other words, the kind
of code you’re complaining about writing. :) Architecturally, this would be a layer on top
of CouchDB, and fairly separable from it, so it’s best done with a plugin or extension like
the ones that have been mentioned already.

I realize that there are mature
projects out there which have very powerful querying capabilities, but for
simple setups a limited querying support would be very useful.

Are you sure you’ve exhausted what CouchDB can do? I don’t know how much experience you
have, but a lot of new users don’t realize the tricks you can do with complex keys, subranges,
grouping, etc.


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