To be fair CouchDB is very explicit that to get any sort of performance, everything must be a view. "Ad-hoc queries" (i.e. queries that are written on the fly instead of uploaded as a view) are clearly stated as "for development only".
Where CouchDB really falls flat is for write-heavy applications. The default configuration in CouchDB is to not reindex a view until it has been read. When a read occurs, any new data in a view that was added since the last read must be re-indexed by executing the map/reduce functions on that data. If you're writing frequently to CouchDB but not reading a lot (as in a data warehouse) the first query you run is going to be extremely slow, since it will need to run map/reduce on a lot of new data. CouchDB doesn't distribute work to multiple nodes like Hadoop, and I've found even simple reduce functions to slow down re-indexing by a factor of 10. I think CouchDB has settings now to update the index on commit, or you could always run a cron job to regularly query the view and force a reindex, but it's still going to be slow.
BigCouch (https://cloudant.com/#!/solutions/bigcouch) might be a potential choice for data warehousing, since it advertises full compatibility with the CouchDB API but offers distributed map/reduce like Hadoop/Hive/etc. I haven't used it though.
Couch is definitely a lot more honest about their limitations than mongo or riak, but my experiences make me hesitant to recommend it to anyone not intimately familiar with those limitations.
Comments
To be fair CouchDB is very explicit that to get any sort of performance, everything must be a view. "Ad-hoc queries" (i.e. queries that are written on the fly instead of uploaded as a view) are clearly stated as "for development only".
Where CouchDB really falls flat is for write-heavy applications. The default configuration in CouchDB is to not reindex a view until it has been read. When a read occurs, any new data in a view that was added since the last read must be re-indexed by executing the map/reduce functions on that data. If you're writing frequently to CouchDB but not reading a lot (as in a data warehouse) the first query you run is going to be extremely slow, since it will need to run map/reduce on a lot of new data. CouchDB doesn't distribute work to multiple nodes like Hadoop, and I've found even simple reduce functions to slow down re-indexing by a factor of 10. I think CouchDB has settings now to update the index on commit, or you could always run a cron job to regularly query the view and force a reindex, but it's still going to be slow.
BigCouch (https://cloudant.com/#!/solutions/bigcouch) might be a potential choice for data warehousing, since it advertises full compatibility with the CouchDB API but offers distributed map/reduce like Hadoop/Hive/etc. I haven't used it though.
Couch is definitely a lot more honest about their limitations than mongo or riak, but my experiences make me hesitant to recommend it to anyone not intimately familiar with those limitations.