Blog - comments

Hi Olivier,DELAYED_DURABILITY doesn't change the SQL Server behavior of opening the data and log fil...
Hi David,Thanks for this demo with write functions. As much I know, SQL Server always access files (...
Olivier Berthommé
Thank you for your feedback. I will build a test environment and realize a guide to deploy Grid Infr...

Hi Greg,

Thanks

great job Dave ! thanks

greg
Blog

dbi services Blog

Welcome to the dbi services Blog! This IT blog focuses on database, middleware, and OS technologies such as Oracle, Microsoft SQL Server & SharePoint, EMC Documentum, MySQL, PostgreSQL, Sybase, Unix/Linux, etc. The dbi services blog represents the view of our consultants, not necessarily that of dbi services. Feel free to comment on our blog postings.

  • Home
    Home This is where you can find all the blog posts throughout the site.
  • Categories
    Categories Displays a list of categories from this blog.
  • Tags
    Tags Displays a list of tags that have been used in the blog.
  • Bloggers
    Bloggers Search for your favorite blogger from this site.
Recent blog posts

I'm currently following the session 'Real-World Performance of Star and Snowflake Schemas' with Michael Hallas, Andrew Holdsworth, John Clarke. It's really a good presentation. the Real Performance team tries to spread messages about how to design for performance. But today I'll not blog about what I've seen but about what I've not seen. Everybody talks about those nice 12c features that are useful in BI workloads, such as adaptive joins, adaptive parallel distribution, vector 'in-memory' aggregation, etc. Nobody talks about Adaptive Bitmap Pruning.

Hits: 45
Rate this blog entry:
0
Continue reading 0 Comments
Usually, the logical replication of changes uses the primary key. Each row updated or deleted generate a statement to be applied on the target, which affects only one row because it accesses with the primary key. If there is no primary key, we need to have something unique and at worst it is the whole row. But sometimes old applications were designed before being implemented into relational database and have no unicity. It it a problem for logical replication? We will see that Dbvisit replicate can address that.
 
Here is the case I encountered at a customer. The application has a master-detail table design, and the detail tables are inserted/deleted all together for the same master key. And there is no primary key, and even nothing unique. The only value that may help is a timestamp but sometimes timestamps do not have the sufficient precision to be unique. And anyway, imagine what happens if we change back the system time, or during daylight saving changes.
 
At dbi services we have very good contact with our partner Dbvisit and it's the kind of question that can be addressed quickly by the support. Anyway, I was at the Oracle Open World and then was able to discuss directly with the Dbvisit replicate developers. There is a solution and it is even documented.

The basic issue is that when the delete occurs, a redo entry is generated for each row that is deleted and then Dbvisit replicate generates an update statement to do the same on the target. But when there are duplicates the first statement will affect several rows and the next statement will affect no rows.

Hits: 109
Rate this blog entry:
0
Continue reading 0 Comments

Do you know Delphix? The first time I heard of it was from Jonathan Lewis. And from Kyle Hailey of course. So it's not only about agile and virtualization. It's a real DBA stuff. So as I did yesterday with Dbvisit #repattack let's install the demo.

Hits: 39
Rate this blog entry:
0
Continue reading 0 Comments

Day 2 at Oracle Open World - Best pratices

Posted by on in Middleware

Today, in this post I will describe some best practices I learned in several sessions. It's always good to see what is adviced by other people that are confronting to other or same challenges.

Hits: 53
Rate this blog entry:
0
Continue reading 0 Comments

Landing on Sunday 28th, after a 13 hours' trip my colleague Franck Pachot and I had just the time to do the registration, go to the hotel, and go back to the "Welcome Reception" where we could eat something. After a night where I could feel the jet lag :-) we where ready to "participate" in this amazing event, the Oracle Open World 2014.

Hits: 201
Rate this blog entry:
1
Continue reading 0 Comments

Oracle Open World is not only conferences but also practice and networking. Today at the OTN lounge have installed the following demos on my laptop:

Hits: 170
Rate this blog entry:
1
Continue reading 0 Comments

The new D2-Client does not correctly display the icon for some formats. This usually happens when the icon.css is not up to date based on the content format in the repository. The solution is to find these formats and update the icon.css.

Hits: 145
Rate this blog entry:
1
Continue reading 0 Comments

It's now several weeks I attended some event about high availability (HA). But what is actually high availability? According to our friend Wikipedia, HA is based on 3 main principals:

Hits: 168
Rate this blog entry:
1
Continue reading 0 Comments

A thread on OTN Forum about Exadata came to the following question: "But how can I monitor if it is effectively used or not?". This is a common question. There are 3 exclusive features coming with Exadata, and instance statistics can show their usage. Even better: two of them can even be checked on your current (non-Exadata) system. And that is good to foresee how Exadata can improve your workload.

Tagged in: Exadata Oracle
Hits: 250
Rate this blog entry:
1
Continue reading 0 Comments

When you learn about SQL Server, you will often hear that a commit transaction is a synchronous operation and that you can trust it. In this blog post, I will provide some details about what we mean by synchronous behavior. The reason is that sometimes, when I talk about the new delayed durability feature provided by SQL Server 2014, there are some confusions. If you want more details on this new feature, please read the blog post of my colleague Stéphane Haby here. A quick shortcut is often the following: writing to the transaction log is synchronous, while writing with the new delayed durability feature is asynchronous.

Hits: 281
Rate this blog entry:
3
Continue reading 2 Comments
AddThis Social Bookmark Button
Deutsch (DE-CH-AT)   French (Fr)

Contact

Contact us now!

Send us your request!

Our workshops

dbi FlexService SLA - ISO 20000 certified.

dbi FlexService SLA ISO 20000

Expert insight from insiders!

Fixed Price Services

dbi FlexService SLA - ISO 20000 certified.

dbi FlexService SLA ISO 20000

A safe investment: our IT services at fixed prices!

Your flexible SLA

dbi FlexService SLA - ISO 20000 certified.

dbi FlexService SLA ISO 20000

ISO 20000 certified & freely customizable!

dbi services Newsletter