By Franck Pachot . A previous blog post explaining what happens for those in ‘Standard Edition One’ had a “don’t worry” in the title because you can upgrade to SE2 with minimal additional cost – except when you have to buy new NUPs – and get only small additional limitation. I didn’t made such a post for people in Standard Edition but there is a case where it can be worrying because of the 2…
By Franck Pachot . Customers reluctant to go to 12c before 12.2, in addition to Standard Edition contract changes when going to 12c, has lead to lot of upgrades to 188.8.131.52 but what about support? Don’t worry. It’s supported for no additional cost until May 2017
By Franck Pachot . In the previous post we have seen how In-Memory Compression Unit map to the physical persistent storage – table extents. Let’s see now how they are mapped to column values, allowing to optimize the scan in a similar way as Exadata Storage Indexes.
By Franck Pachot . Oracle In-Memory is an hybrid solution: an In-Memory Column Store in addition to the traditional Row Store. In the IMCS, data is stored in IMCU (In-memory compression units) and metadata is in SMU (Snapshot Metadata Units) In the row store, data is stored in datafile extents and metadata is stored in the dictionary (and in datafile header since Locally managed Tablespaces). Let’s see how they map to eachothers.
By Franck Pachot . In the ‘traditional’ row store, the indexes are maintained at the same time as rows are changed. It’s different with the In-memory Column Store. Changes are maintained by background processes. When rows are changed, the Snapshot Metadata Units (SMU) logs the changes and In-Memory Compression Units (IMCU) are re-populated asynchronously. Let’s see an example.
By Franck Pachot . I’m currently presenting at Swiss BI Day in Geneva about Oracle In-Memory option to improve analytic queries. Here are the slides, uploaded to SlideShare.
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.
By Franck Pachot . At our bi-annual dbiXchange I was talking with Nicolas Jardot about his presentation on Result Cache (don’t forget Jérome witt session about RC at DOAG) where he has shown an unexpected behavior on ‘fetch first n rows queries’. That behavior – if it is not a bug – can also be a good thing when using offset queries.