I’ve had countless emails from readers asking for a technical analysis of what Oracle announced at Openworld 2012 pertaining to the X3 refresh of Exadata Database Machine. I attended the show, fell ill and subsequently had a a lot of work backlog to clear. I will get to this next week and, not surprising to readers of this blog, I’ll take aim on the following words: “Database In-Memory Machine” as they appear in the new marketing nickname for Exadata Database Machine.
Yes, I will blog the matter but would first like to recommend the following excellent blog posts by @flashdba as they relate to “Database In-Memory Machine”:
Note: Part II has one tiny bit of errata as discussed in the comment section of the post. The post speaks of the cache hierarchy of X3 and includes Exadata Storage Server DRAM in the aggregate. I need to point out that we know from reading the myriads of public information on the matter (Oracle’s whitepapers, employee blogs and Expert Oracle Exadata (Apress)) that the DRAM in Exadata Storage Server cells is not used for cache. DRAM in the storage servers is used for management (metadata) of Exadata Smart Flash Cache contents, Storage Indexes metadata and buffering (IB dend/receive buffers, HCC decompression output, etc). The cache hierarchy of X3 is quite succinctly host DRAM (SGA buffers and Results Cache) and Exadata Smart Flash Cache (the PCI flash devices accessed via SCSI disk driver through the Linux block I/O layer in the cells).