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A Serverless Standby Database called Oracle Autonomous Data Guard

By Franck Pachot

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Announced by Larry Ellison last week, here it is: the Autonomous Data Guard. You can try it, unfortunately not on the Free Tier.
First you create an Autonomous Database (ATP or ADW) and then you enable Autonomous Data Guard.

DBPod – le podcast Bases de Données

By Franck Pachot

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J’essaie quelque chose de nouveau. Je publie beaucoup en anglais (blog, articles, présentations) mais cette fois quelque chose de 100% francophone. En sortant du confinement, on reprend les transports (train, voiture,…) et c’est l’occasion de se détendre en musique mais aussi de s’informer avec des podcasts. J’ai l’impression que c’est un format qui a de l’avenir: moins contraignant que regarder une video ou ou lire un article ou une newsletter. Alors je teste une plateforme 100% gratuite: Anchor (c’est un peu le ‘Medium’ du Podcast).

Oracle Autonomous Linux: cron’d ksplice and yum updates

By Franck Pachot

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Oracle Enterprise Linux (OEL) is a Linux distribution which is binary compatible with Red Hat Enterprise Linux (RHEL). However, unlike RHEL, OEL is open source, free to download, free to use, free to distribute, free to update and gets free bug fixes. And there are more frequent updates in OEL than in CentOS, the free base of RHEL. You can pay a subscription for additional support and features (like Ksplice or Dtrace) in OEL. It can run the same kernel as RHEL but also provides, still for free, the ‘unbreakable kernel’ (UEK) which is still compatible with RHEL but enhanced with optimizations, recommended especially when running Oracle products.

Oracle 12c – global partial index

By Franck Pachot

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We have an incredible number of possibilities with Oracle. Yes, an index can be global (indexing many partitions without having to be partitioned itself on the same key) and partial (skipping some of the table partitions where we don’t need indexing). In the previous post of this series of small examples on recent features I partitioned a table, with covid-19 cases per day and per country, partitioned on range of date by interval. The index on the country code (GEOID) was not very efficient for data ingested per day, because countries are scattered through all the table. And then I have reorganized the old partitions to cluster them on countries.

My global index on country code is defined as:

Oracle 12c – reorg and split table with clustering

By Franck Pachot

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In this series of small examples on recent features, I have imported in a previous post, the statistics of covid-19 per day and per countries. This is typical of data that comes as a time-series ordered by date, because this is how it is generated day after day, but where you probably want to query from another dimension, like per countries.

Oracle 12c – peak detection with MATCH_RECOGNIZE

By Franck Pachot

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This post is part of a series of small examples of recent features. I’m running this in the Oracle 20c preview in the Oracle Cloud. I’ll show a very basic example of “Row Pattern Recognition” (the MATCH_RECOGNIZE clause in a SELECT which is documented as “row pattern matching in native SQL” feature by Oracle”). You may be afraid of those names. Of course, because SQL is a declarative language there is a small learning curve to get beyond this abstraction. Understanding procedurally how it works may help. But when you understand the declarative nature it is really powerful. This post is there to start simple on a simple table with time series where I just want to detect peaks (the points where the value goes up and then down).

What is a serverless database?

By Franck Pachot

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After reading the https://cloudwars.co/oracle/oracle-deal-8×8-larry-ellison-picks-amazons-pocket-again/ paper, I am writing some thoughts about how a database can be serverless and elastic. Of course, a database needs a server to process its data. Serverless doesn’t mean that there are no servers.

Oracle 18c – select from a flat file

By Franck Pachot

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This post is the first one from a series of small examples on recent Oracle features. My goal is to present them to people outside of Oracle and relational databases usage, maybe some NoSQL players. And this is why the title is “select from a flat-file” rather than “Inline External Tables”. In my opinion, the names of the features of Oracle Database are invented by the architects and developers, sometimes renamed by Marketing or CTO, and all that is very far from what the users are looking for. In order to understand “Inline External Table” you need to know all the history behind: there were tables, then external tables, and there were queries, and inlined queries, and… But imagine a junior who just wants to query a file, he will never find this feature. He has a file, it is not a table, it is not external, and it is not inline. What is external to him is this SQL language and what we want to show him is that this language can query his file.