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Nicolas Jardot

SQL Patch: Another way to change the plan without changing the code

By | Application integration & Middleware | 5 Comments

Recently, at a customer site, I faced a performance issue. However, as often the statement is embedded in the application so it’s not possible to rewrite the query. In this blog post, we’ll change the execution plan to solve the problem without changing the code – thanks to SQL Patch. The faulty statement was part of a daily job that was configured and started from the application during the night. Every night, the statement failed…

 
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Franck Pachot

Oracle 12c Adaptive Plan & inflection point

By | Database management, Oracle | One Comment

The Oracle 12c Adaptive Plan feature was already presented by Nicolas Jardot in OOW 2013: Solving customer issues with the 12c Optimizer. I recently had to answer several questions about its behavior at execution time. Maybe the term ‘adaptive’ is misleading. It’s not that a join will stop and restart to another join method. Even with adaptive plan there will only be one join method to be applied. The feature only defers a decision that…

 
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Nicolas Jardot

OOW 2013: Solving customer issues with the 12c Optimizer (III) – Histogram on varchar2 column

By | Application integration & Middleware | No Comments

It has been a long time since the last Oracle 12c Optimizer article, but this one is the last on the series about customer issues in Oracle 11g. The goal of that series is to show how the new version 12c of Oracle Database helps solving these issues. This blog posting focuses on a well know Oracle behavior when gathering histograms on a varchar2 column. The three cases have been presented during the session “Solving…

 
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Nicolas Jardot

UKOUG Tech13: Optimizer & SQL statements – hint or not hint that’s the question

By | Technology Survey | No Comments

It’s the final day of Tech13, less sessions but still good topics. Mainly about the Oracle’s optimizer: looking at the execution plans and a debate about hinting SQL statements. I will focus on the hint topic in this blog. Due to trip planning it’s a much shorter day, less time for attending sessions and less time for blogging. I will focus on the debate between Tony Hasler and Jonathan Lewis about how the optimizer takes…

 
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Nicolas Jardot

UKOUG Tech13: Day 3 – Virtualization and Oracle 12c Optimizer

By | Technology Survey | No Comments

Another full day in Manchester, I choose to follow a stream a little bit different in the morning. So it will not be all about the Oracle Optimizer 12c today, but more about O.S and virtualization. Virtualization is an interesting topic but it’s also complex because if the concept seems simple, there are problematics with the licensing, the support and the performance. Why use Oracle VM? Everyone thinks about VMware when speaking about the first…

 
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Pierre Sicot

UKOUG Day 2: Exadata Management Deep Dive with OEM Cloud 12c

By | Technology Survey | No Comments

I started the second day ay UKOUG with an Exadata Management Deep dive with Oracle Enterprise Manager Cloud 12c. Through a certain numer of plugins, Oracle Enterprise Manager Cloud 12c offers an integrated view of hardware and software. In Enterprise Management Cloud 12c you have access to the following menus: Software Cell Management: Cell home page and performance page Workload distribution by database Interprets immediately what’s happening Performance workload distribution may help analyze analyses performance…

 
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Nicolas Jardot

UKOUG Tech13 “Super Sunday”: dbi services is here!

By | Technology Survey | No Comments

Today was the first day of UKOUG Tech13: 4 days about Oracle Technology. This year, 7 streams started today (3 last years). I also had a slot to give my presentation about the Optimizer behavior in 12c. The day started with a little delay in registration: My collagues Pierre and Philippe were not correctly registered and didn’t get their badge right away, but everything was solved before the start of the sessions. Speaker time I…

 
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Pierre Sicot

UKOUG Day 1: Oracle Optimizer 12c, Cost Based Optimizer, Exadata

By | Technology Survey | No Comments

Today was the first day of the United Kingdom Oracle User Group (UKOUG) – usually called the Super Sunday! I already participated in today’s first session three weeks ago in Geneva, but my colleague Nicolas Jardot was talking about Solving Critical Issues with the 12c Optimizer, covering histogram collection, temporary table statistics and adaptive query optimization. There were around thirty people at his session, and a lot of UKOUG speakers were very interested and asked…

 
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Nicolas Jardot

Oracle Open World 2013: 3rd day – Hands on lab, Optimizer tips and Microsoft Cloudn

By | Technology Survey | No Comments

Today, I’ll talk about the 3rd day at Oracle OpenWorld 2013 and I’ll be shorter than yesterday, too much text. Actually, it’s difficult to have good pictures during the conferences. So what’s the program in this blog: a “hands on lab” session about Linux management, a keynote from Microsoft and few tips about the optimizer. Too much text and not enough photos, I already told that the event is impressive: And it’s just one place!…

 
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Nicolas Jardot

OOW 2013 : Solving customer issues with the 12c Optimizer (I) – Adaptive execution plans

By | Application integration & Middleware | No Comments

During the last year, I faced many performance issues at customer sites with their applications. To solve the issues, I had to implement some workarounds because in most cases, the application code couldn’t be changed. As Oracle 12c is now available since more than 2 month, I decided to focus on how this new release will help our customers to solve their performance issues. I will present you 3 real customer cases reproduced in lab…

 
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