http://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660Nathaniel, I read some about it. What seems to be missing is the concept of updatable data source. That is the problem that I am trying to solve at this stage. And the main goal is to reduce the amount of work that I have to do whenever I have to update a document to a minimum. http://ayende.com/3910/designing-a-document-database-looking-at-views#comment6http://ayende.com/3910/designing-a-document-database-looking-at-views#comment6Fri, 20 Mar 2009 11:13:55 GMTAyende, This is the problem that map-reduce-merge was intended to solve, relational algebra (joins especially) in map reduce. Sorry the link before was an ACM one, but if you google for map-reduce-merge there is a decent amount of info out there. This is what I am working on implementing at the moment. http://ayende.com/3910/designing-a-document-database-looking-at-views#comment5http://ayende.com/3910/designing-a-document-database-looking-at-views#comment5Tue, 17 Mar 2009 14:41:40 GMTSecond thought is that such join will probably have the same cost as fetching data 'by hand' in map function... http://ayende.com/3910/designing-a-document-database-looking-at-views#comment4http://ayende.com/3910/designing-a-document-database-looking-at-views#comment4Tue, 17 Mar 2009 07:04:34 GMTLet's stick to the invoice db example. Suppose we have invoice documents with buyerTaxID and corporate customer database, customers identified also by Tax ID. And we have a view Tax ID -> Customer (vCustomerByTaxID) . Then, when doing mapping on invoices, we could tell the system to fetch customer data from vCustomerByTaxID, where key is in invoice's buyerTaxId field. Something like select d as doc, vCustomerByTaxId.Value as customer from docs join vCustomerByTaxId on docs.buyerTaxId http://ayende.com/3910/designing-a-document-database-looking-at-views#comment3http://ayende.com/3910/designing-a-document-database-looking-at-views#comment3Mon, 16 Mar 2009 19:05:09 GMTRafal, Can you give me an example please? http://ayende.com/3910/designing-a-document-database-looking-at-views#comment2http://ayende.com/3910/designing-a-document-database-looking-at-views#comment2Mon, 16 Mar 2009 18:39:29 GMTRegarding the problem with joins, maybe there should be an option to left-join with an already existing view by its key? Not necessarily in v 1.0. http://ayende.com/3910/designing-a-document-database-looking-at-views#comment1http://ayende.com/3910/designing-a-document-database-looking-at-views#comment1Mon, 16 Mar 2009 18:37:04 GMT