>>>>> "Carlos" == Carlos Mennens <carlos.menn...@gmail.com> writes:
Carlos> Looking to read your feedback and / or opinions. Here's what I wrote on the Smalltalk Seaside mailing list a few weeks back: I've given a talk a few times about "forget the ORM". The slides are up on http://www.slideshare.net/RandalSchwartz/forget-the-orm The key thing that separates a lot of these newer databases is that you can't have all three of consistency, availability, and performance at once... you have to sacrifice something. Traditional SQL databases favored consistency over everything, but who cares if your blog page says "read the 6 comments on this item" for a couple of seconds when there are really 7 because one just got added. The new databases give options for higher availability or performance at the cost of consistency. Some, like Riak (interviewed at http://twit.tv/floss129), actually let you select on each request how consistent you want the results, thus controlling how fast you get the response. Thus, for the front page of a blog, you can say "give me a result that any 1 of the 3 replicas has", but when you finally drill into the comments, you say "give me a result that all 3 replicas agree on". Of course, these are all *eventually* consistent on the order of tens or hundreds of milliseconds, but by allowing "almost correct" results, things are a lot zippier. (It also works that way on write... you can say "come back when any 1 replica says it has it" or "come back only when all 3 replicas confirm write".) So, it's not so much that you get schemaless key/value store (although that's a frequent feature)... it's that these aren't traditional databases in a lot of ways. -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <mer...@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.posterous.com/ for Smalltalk discussion -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
