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Franck Pachot

18c: Order by in WITH clause is not preserved

By | Oracle | No Comments

By Franck Pachot . For a previous post I’ve run on 18c a script of mine to get the V$MYSTAT delta values between two queries. This script (new version available on GitHub) generates the queries to store some values and subtract them on the next execution. But I had to fix it for 18c because I relied on some order by in a CTE which is lost in 18c. The idea was to get the…

 
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Stéphane Haby

SQL Server 2016: temporal table with In-Memory

By | Technology Survey | One Comment

In SQL Server 2016 CTP 3.0, temporal tables with In-Memory OLTP is supported. At the JSS2015 (Journée SQL Server 2015), I have presented a little demo about temporal table with a table In-Memory. This article is a complement of my presentation and a good add to my series of Temporal Table. My first step is to create the temporal In-Memory table: CREATE TABLE [dbo].[Animals2] ( [AnimalId] [int] IDENTITY(1,1) NOT NULL, [Name] [varchar](200) COLLATE French_CI_AS NOT…

 
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Stéphane Haby

Journées SQL Server (JSS) 2015 à Paris – Sessions & Sponsoring

By | Technology Survey | No Comments

Faisant suite à la première annonce de David Barbarin sur les journées SQL Server du 30 novembre et 1er décembre, j’ai le plaisirs de vous inviter à venir nous voir également à notre stand. Effectivement, comme l’année passée, nous sommes heureux d’être à nouveau sponsors GOLD de l’événement et seront placés comme le schéma ci-dessous vous le montre. N’hésitez pas à venir nous rencontrer sur notre stand! Nous aurons également le privilège d’animer 2 sessions…

 
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David Barbarin

Journées SQL Server 2015 à Paris – 30 novembre et 1er décembre

By | Technology Survey | No Comments

Les journées SQL Server se dérouleront dans un mois à Paris dans les locaux de Microsoft. L’agenda n’a été qu’en parte dévoilé mais c’est avec plaisir que je peux dores et déjà vous annoncer que dbi services sera de la partie cette année encore en tant que speaker et sponsor de l’événement. Pour ma part j’aurai le plaisir de vous y retrouver une fois de plus autour d’une session In-memory 2016 avec notamment les index…

 
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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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