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All posts by Franck Pachot

Franck Pachot
Technology Leader
Principal Consultant

OCM 12cFranck Pachot has 20 years of experience in Oracle databases. Through his expertise as a DBA, Oracle expert, data architect, and performance specialist, he is able to cover all database areas: architecture, data modeling, database design, tuning, operation, and training. Franck knows how to enable an efficient collaboration between the developers and the operational team when it comes to troubleshooting issues or performance tuning.

RSSOracle ACEOracle ACE Franck is Oracle Certified Master (OCM 12c), Oracle ACE Director and proud member of Oraworld-team and Oak Table.

Cracow (PL), Sept. 1st

12cR2 Statistics Advisor: Do you gather statistics in the way the optimizer expects them?
Swiss Oracle User Group

Leman: Calculer les statistiques comme prévu par l'optimiseur
Baden: Single-Tenant 12.2
San Francisco, Oct 1st

Multitenant: Trust It by Understanding Beyond What Is Documented
Nürnberg, Nov, 21st

Multitenant internals
From Transportable Tablespace to Pluggable Databases
Join Methods: Nested Loop, Hash, Sort, Merge, Adaptive

Franck Pachot

Oracle Cloud: script to stop all PaaS services

By | Cloud, Oracle | No Comments

With metered cloud services, keeping all your instances running may become expensive. The goal is to start them only when you need them. Here is a script that stops all instances you have on the Oracle Cloud Service PaaS. You can schedule it for example to stop them at the end of the business day, or when they are not active for a long time. The scripts use the REST API called with curl, JSON…

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Franck Pachot

Postgres vs. Oracle access paths I – Seq Scan

By | Oracle, Postgres | 5 Comments

Here is the first test I’ve done for my Postgres vs. Oracle access paths series and the first query did a sequential scan. It illustrates the first constant you find in the documentation for the query planner: seq_page_cost (floating point) Sets the planner’s estimate of the cost of a disk page fetch that is part of a series of sequential fetches. The default is 1.0.  

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Franck Pachot

Postgres unique constraint

By | Postgres | No Comments

I’ll start a series on Postgres vs. Oracle access paths because I know Oracle and I learn Postgres. While preparing it, I came upon some surprises because I’m so used to Oracle that I take some behavior as granted for any SQL databases. I recently posted a tweet about one of them, comparing latest Postgres version to earliest Oracle version I have on my laptop. The goal of the tweet was exactly what I said…

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Franck Pachot

Postgres vs. Oracle access paths – intro

By | Oracle, Postgres | 2 Comments

This is the start of a series on PostgreSQL execution plans, access path, join methods, hints and execution statistics. The approach will compare Postgres and Oracle. It is not a comparison to see which one is better, but rather to see what is similar and where the approaches diverge. I have a long experience of reading Oracle execution plans and no experience at all on Postgres. This is my way to learn and share what…

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Franck Pachot

PostgreSQL on Cygwin

By | Postgres | No Comments

I run my laptop with Windows 10 for office programs, and VirtualBox machines with Linux for the big stuff (Oracle databases). I have also Cygwin installed on Windows for GNU programs. I wanted to quickly install PosgreSQL and rather than installing it in a Linux VM, or as a Windows program, I installed the Cygwin version of it. Here is how.  

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Franck Pachot

ODA X6 installation: re-image

By | Oracle | No Comments

The Oracle Database Appliance is shipped with a bare-metal installation which may not be the latest version. You may want to have it virtualized, or get the latest version to avoid further upgrade, or install an earlier version to be in the same configuration as another ODA already in production. The easiest for all cases is to start with a re-image as soon as the ODA is plugged. This post is not a documentation, just…

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Franck Pachot

12cR2 Application Containers and Foreign Keys

By | Database management, Oracle | 2 Comments

Application Container brings a new way to share data among databases, and adds a new dimension to referential integrity. A foreign key in an application PDB can reference a row belonging to a root data link table. But then, should a delete on the root validate that there are no orpheans in the application PDBs? And what if those PDBs are closed at the time of this delete? Here is a small example.  

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