By Franck Pachot . I wanted to check if Exadata predicate offloading can occur on Global Temporary Tables. Actually, I thought it did not and I was wrong. I was ready to post that as an hypothesis for https://community.oracle.com/thread/3903836 but, before any post to forums, I try to test what I say because I may be wrong, or things may…
By Franck Pachot . When you want to minimize the backup or restore duration, you can parallelize RMAN operations by allocating multiple channels. If you are in cluster, you can open channels from several nodes. Let’s see why, how, and a strange issue: need to set cell_offload_processing=false even if not on Exadata. Reason Why do I want to run backup…
By Franck Pachot . Next Tuesday in Geneva I’m presenting Oracle In-Memory Column Store to Business Intelligence people at the Swiss BI Day After defining what is an analytic query, I show the different approaches to optimize that in Oracle, IMCS being the latest one. Here are some details about that slide. What is an analytic query? First definition –…
By Franck Pachot . For Exadata, oracle has introduced an ‘EXADATA’ mode which sets a high transfer rate (with IOTFRSPEED as in NOWORKLOAD statistics) and set a MBRC (as in WORKLOAD statistics). Those values are set rather than gathered because all the SmartScan optimization done at storage cell level, which makes the multiblock reads less expensive, is difficult to measure…
By Franck Pachot . A thread on OTN Forum about Exadata came to the following question: “But how can I monitor if it is effectively used or not?”. This is a common question. There are 3 exclusive features coming with Exadata, and instance statistics can show their usage. Even better: two of them can even be checked on your current (non-Exadata)…
By Franck Pachot . In a previous blog, I discussed the difference between rownum and row_number(), in particular their behaviour in implicitely adding a first_rows(n) to the optimizer. That reminded me that I forgot to blog about an issue I encountered and which concerns both approaches. It was on an Exadata: a nice full table scan with smartscan was taking…
Last february, I had the chance to attend an Oracle presentation about ODA: Oracle Database Appliance. I found it interessant to share what I have learned about this technology. Which, I confess, convinced me. Summary Before developing the software and hardware components, here is a small overview of ODA. ODA is an all in one solution providing Hardware, Operating System,…
