Here are some quick thoughts on Oracle 12c…
First, I appreciate the tone of the announcements. They were sober and smart.
I love the pluggable database stuff. It fits into the trends I have discussed here and here. Instead of consolidating virtual machines on multi-core processors and incurring the overhead of virtual operating systems Oracle has consolidated databases into a single address space. Nice.
But let’s be real about the concept. The presentations make it sound like you just unplug from server A and plug into server B… no fuss or muss. But the reality is that the data has to be moved… and that is significant. Further, there are I/O bandwidth considerations. If database X runs adequately on A using 5GB/sec of read bandwidth then there better be 5GB/sec of free bandwidth on server B. I know that this is obvious… but the presentations made it sound magic. In addition 12c added heat maps and storage tiering… but when you plug-in the whole profile of what is hot for that server changes. This too is manageable but not magic. Still, I think that this is a significant step in the right direction.
I also like the inclusion of adaptive execution plans. This capability provides the ability to change the plan on-the-fly if the execution engine determines that the number of rows it is seeing from a step differs significantly from the estimate that informed the optimizer. For big queries this can improve query performance significantly… and this is especially the case because prior to 12c Oracle’s statistics collection capability was weak. This too has been improved. Interestingly the two improvements sort of offset. With better statistics it is less likely that the execution plan will have to adapt… but less likely does not mean unlikely. So this feature is a keeper.
I do not see any of the 12c major features significantly changing Oracle’s competitive position in the data warehouse market. If you run a data warehouse flat-out you will not likely plug it elsewhere… the amount of data to move will be daunting. The adaptive execution plan feature will improve performance for a small set of big queries… but not enough to matter in a competitive benchmark. But for Oracle shops adaptive execution is all positive.