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Oracle

Franck Pachot

You are in Standard Edition, when to worry?

By | Database Administration & Monitoring, Oracle | 4 Comments

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…

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Franck Pachot

Mapping In-memory Column Store to datafile Row Store extents

By | Database Administration & Monitoring, Oracle | No Comments

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.

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Franck Pachot

In-memory trickle repopulation

By | Database Administration & Monitoring, Oracle | No Comments

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.

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