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Franck Pachot

Franck Pachot

Oracle Autonomous Linux: cron’d ksplice and yum updates

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . 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…

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Franck Pachot

The Oracle ACE program ♠ what it is not ♠

By | Database Administration & Monitoring | 4 Comments

By Franck Pachot . I had a few questions about the Oracle ACE program recently and I thought about putting some answers there. Of course, that’s only my point of view, there’s an official web page: https://www.oracle.com/technetwork/community/oracle-ace/index.html The program is flexible and open, with a large diversity of people, technologies, contributions, levels,… Then rather than explaining what it is, which would be limiting, I’ll rather tell you… what it is not. It is not a…

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Franck Pachot

Some myths about PostgreSQL vs. Oracle

By | Oracle, Postgres | One Comment

By Franck Pachot . I originally wrote this as a comment on the following post that you may find on internet: https://www.2ndquadrant.com/en/blog/oracle-to-postgresql-reasons-to-migrate/ but my comment was not published (many links in it… I suppose it has been flagged as spam?) so I put it there. You should never take any decision on what you read on the internet without verifying. It is totally valid to consider a move to Open Source databases, but doing it…

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Franck Pachot

Oracle non-linguistic varchar2 columns to order by without sorting

By | Cloud, Oracle | No Comments

By Franck Pachot . Sorting data is an expensive operation and many queries declare an ORDER BY. To avoid the sort operation you can build an index as it maintains a sorted structure. This helps with Top-N queries as you don’t have to read all rows but only those from a range of index entries. However, indexes are sorted by binary values. For NUMBER or DATE datatypes, the internal storage ensures that the order is…

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Franck Pachot

No{Join,GroupBy}SQL – Analytic Views for BI

By | Cloud, Oracle | No Comments

By Franck Pachot . Advocates of NoSQL can query their structures without having to read a data model first. And without writing long table join clauses. They store and query a hierarchical structure without the need to follow relationships, and without the need to join tables on a foreign key name, in order to get a caption or description from a lookup table. The structure, like an XML or JSON document, provides metadata to understand…

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Franck Pachot

Oracle 12c – global partial index

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . 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…

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Franck Pachot

Oracle 12c – reorg and split table with clustering

By | Cloud, Database Administration & Monitoring, Oracle | 2 Comments

By Franck Pachot . 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. If you want to ingest data faster, you keep it…

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Franck Pachot

Oracle 12c – peak detection with MATCH_RECOGNIZE

By | Cloud, Database Administration & Monitoring, Oracle | 2 Comments

By Franck Pachot . 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…

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Franck Pachot

Oracle 12c – pre-built join index

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . 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 have created a few tables in the previous post with a mini-snowflake scheme: a fact table CASES with the covid-19 cases per country and day. And a dimension hierarchy for the country with COUNTRIES and CONTINENTS tables. This title may look strange for people used…

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Franck Pachot

What is a serverless database?

By | AWS, Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . 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. Serverless as not waiting for server provisioning The first idea of “serverless” is about provisioning. In the past when a developer required a new database to start a new project she had to…

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