Good material Wout. I also added a reference to the page about multi document transactions to the page, as it's kind of relevant when modeling docs with relationships.
regards, Andrius Juozapaitis On Tue, Apr 14, 2009 at 6:56 AM, Jason Smith <[email protected]> wrote: > That's cool. Some thoughts: > > 1. I changed the first sentence a little to better comply with the > document's CC-A license. > > 2. Do you think the word "Joins" should be added somewhere to get into > Google? IMO this document is a better way to learn than the slightly more > dense ViewCollation page. > > 3. Couch is different from App Engine WRT (at least) transactions and > indexing. Most people can use App Engine somewhat quickly because there is > still a facility for transactions involving several objects. (It's not a > RDBMs but you can still do it.) Whereas with CouchDB, the unit of atomicity > is the document. Speaking of documents, I'm not sure there is as big of a > performance penalty for large Couch documents vs. large App Engine models. > App Engine indexes every possible combination of attributes that you might > ever query against, but in CouchDB, you write your own indexes which, stored > separately from the main data. So you could have a large complex document > (for atomic modification), but mostly read its data via various views which > cherry-pick the important parts. > > In short, I'm not sure Couch has the same performance characteristics as App > Engine for data. Specifically, I would be tempted to use the "list of keys" > method for as long as possible since you can get to your data in one view > request. (But I'm no expert.) > > Still, for the large portion of applications which don't have major > performance requirements, this is a great document! I like how it teaches > how to do "joins" without using scary words like "view collation" and > "map/reduce"! > > Wout Mertens wrote: >> >> Hi everyone, >> >> I made a stab at translating a Google document about modeling entity >> relationships into CouchDB lingo. >> >> http://wiki.apache.org/couchdb/EntityRelationship >> >> Comments welcome. >> >> Wout. >> > > -- > Jason Smith > Proven Corporation > Bangkok, Thailand > http://www.proven-corporation.com >
