On Fri, Mar 20, 2009 at 11:27 AM, thad <[email protected]> wrote: > On 3/19/09, Winelfred G. Pasamba <[email protected]> wrote: >> one of the very nice things about Oracle is RAC. >> > Good if you can find open source that scale like RAC.
you have to understand between "shared-everything" and "shared-nothing " architectures in a distributed system when you are talking about scalability guys... oracle rac is a shared-everything architecture while mysql cluster is a shared-nothing architecture.. the problem with rac is that it shared its backend storage... thus the bottleneck and scalability problem comes when more nodes added to a RAC especially when the nodes are doing a write operations... furthermore.. oracle 11g can support now upto 100 nodes... in real implementations.. it shows negative scalability because of the nodes coordinating with each other to communicate who owns this resource (eg. lock ownership). with that scalability problem of shared-everything architecture... here comes the shared-nothing architecture.. shared-nothing architecture where each node is independent and self-sufficient and there is no single point of contention across the system... one good example and demonstrated how effective shared-nothing architecture and scale almost *infinitely* by adding an inexpensive node since there is no single bottleneck to slow down the system is google database (using a flat file spreads across the system)... amazon is doing this also... with a massive read and write transactions.. shared-nothing is the logical choice here... i have experienced with oracle rac (10gR2) and experienced how it was bog down the whole RAC system too.. tsk tsk tsk there are pros and cons to everything... not siding with joebert as i know where is coming from... he just simply understand his database needs and just a practical person that he simply knows what database works for him... for him.. why buy an apple if i need an orange? in short.. know your workload first and choose what database is right for you... fooler. _________________________________________________ Philippine Linux Users' Group (PLUG) Mailing List http://lists.linux.org.ph/mailman/listinfo/plug Searchable Archives: http://archives.free.net.ph
