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Oracle

Jérôme Dubar

ODA: odacli now supports Data Guard in 19.8

By | Database Administration & Monitoring, Database management, Hardware & Storage, Operation systems, Oracle | 2 Comments

Introduction I’ve been dreaming of this kind of feature: just because most of the ODA configurations now include Disaster Recovery capabilities, through Data Guard or Dbvisit standy. If Dbvisit will obviously never be integrated to odacli, the lack of Data Guard features is now solved by the very latest 19.8 ODA software appliance kit. How Data Guard was implemented before 19.8? Those who have been using ODA and Data Guard for a while know that…

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Franck Pachot

The myth of NoSQL (vs. RDBMS) “a simpler API to bound resources”

By | NoSQL, Oracle | No Comments

By Franck Pachot . NoSQL provides an API that is much simpler than SQL. And one advantage of it is that users cannot exceed a defined amount of resources in one call. You can read this in Alex DeBrie article https://www.alexdebrie.com/posts/dynamodb-no-bad-queries/#relational-queries-are-unbounded which I take as a base for some of my “Myth of NoSQL vs RDBMS” posts because he explains very well how SQL and NoSQL are perceived by the users. But this idea of…

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Clemens Bleile

Oracle ASH SQL_PLAN_LINE_ID in adaptive plans

By | Oracle | No Comments

There are several methods to find out where time is spent in an execution plan of a query running in an Oracle database. Classical methods like SQL Trace and running a formatter tool like tkprof on the raw trace, or newer methods like SQL Monitor (when the Tuning Pack has been licensed) or running a query with the GATHER_PLAN_STATISTICS-hint (or with statistics_level=all set in the session) and then using DBMS_XPLAN.DISPLAY_CURSOR(format=>’ALLSTATS LAST’). However, what I often…

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Franck Pachot

A Serverless Standby Database called Oracle Autonomous Data Guard

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

By Franck Pachot . 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. You know that “Autonomous” is the marketing brand for the services that automate a lot of things, sometimes based on features that are in Oracle Database for a long time. So let’s…

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Ali Asghari

Create and configure an Oracle linked server in SQL Server Instance

By | Database Administration & Monitoring, Database management, Oracle, SQL Server | No Comments

What is Linked server ? Now a days in each company we have different applications and each one of them have different needs in term of databases support. When data exists on multiple databases the management become a little bit hard. For exemple moving some data from an Oracle database to a SQL Server database is not easy. A linked servers is configured to enable the Database Engine to execute a Transact-SQL statement that includes…

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Franck Pachot

DBPod – le podcast Bases de Données

By | AWS, Cloud, Database Administration & Monitoring, Database management, Development & Performance, DevOps, NoSQL, Oracle, Postgres, SQL Server | No Comments

By Franck Pachot . 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…

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Franck Pachot

19c: scalable Top-N queries without further hints to the query planner

By | Oracle | No Comments

By Franck Pachot . The FETCH FIRST … ROWS ONLY syntax arrived in Oracle 12c and is much more convenient than using a subquery with ‘ORDER BY’ wrapped in a “WHERE ROWNUM < …” around it. But as I mentioned in a previous post it required the FIRST_ROWS() hint to get correct estimations. In SQL you don’t want to overload your code for performance, right? The RDBMS optimizer does the job for you. This was…

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Franck Pachot

The myth of NoSQL (vs. RDBMS) “joins dont scale”

By | AWS, Database Administration & Monitoring, NoSQL, Oracle, Postgres, SQL Server | 13 Comments

By Franck Pachot . I’ll reference Alex DeBrie article “SQL, NoSQL, and Scale: How DynamoDB scales where relational databases don’t“, especially the paragraph about “Why relational databases don’t scale”. But I want to make clear that my post here is not against this article, but against a very common myth that even precedes NoSQL databases. Actually, I’m taking this article as reference because the author, in his website and book, has really good points about…

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Franck Pachot

Oracle ACFS: “du” vs. “df” and “acfsutil info”

By | Oracle | No Comments

By Franck Pachot . This is a demo about Oracle ACFS snapshots, and how to understand the used and free space, as displayed by “df”, when there are modifications in the base parent or the snapshot children. The important concept to understand is that, when you take a snapshot, any modification to the child or parent will [[email protected] ~]$ asmcmd lsdg DATAC1 State Type Rebal Sector Logical_Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files…

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Marc Wagner

POUG 2020 Workshop Day 1

By | Oracle | No Comments

I had the opportunity to participate to POUG day 1 and wanted through this blog to share some of my feedback on the interesting sessions I could follow. First of all, I would like to mention the great introduction done by the staff team and the great organization. POUG staff team could adapt to the coronavirus situation and organized excellent POUG virtual days. Well done!

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