By Franck Pachot . On my Oracle Cloud Free Tier Autonomous Transaction Processing service, a database that can be used for free with no time limit, I have seen this strange activity. As I’m running nothing scheduled, I was surprised by this pattern and looked at it by curiosity. And I got the idea to take some screenshot to show…
Introduction Let’s have a look at how to make Oracle database as simple as it was before. Oracle database is a great piece of software, yes it’s quite expensive, but it’s still the reference and most of the companies can find a configuration that fits their needs according to a budget. Another complain about Oracle is the complexity: nothing is…
SQL Server 2019 RC1 was released out a few weeks ago and it is time to start blogging about my favorite core engine features that will be shipped with the next version of SQL Server. Things should not be completely different with the RTM, so let’s introduce the accelerated database recovery (aka ADR) which is mainly designed to solve an…
I had the opportunity to test the new Dorada 6000 V3 All-Flash storage system. See what the all-new Dorado 6000 V3 All-Flash Storage system is capable as storage for your database system. Before you read This is a series of different blog posts: In the first blog post, I talk about “What you should measure on your database storage and…
Few months ago I attended to the Franck Pachot session about Microservices and databases at SOUG Romandie in Lausanne on 2019 May 21th. He covered some performance challenges that can be introduced by Microservices architecture design and especially when database components come into the game with chatty applications. One year ago, I was in a situation where a customer installed…
In this blog post let’s go back to the roots (DBA concern) with a discussion with one of my friends about a weird transaction locking issue. In fact, this discussion was specifically around two questions. The first one was why SQL Server continues to use shared locks in RCSI mode leading to blocking scenarios and the second one was about…
Below, I will try to explain, a particular case for the general error : ORA-01555 snapshot too old error.. Normally, when we have this error, we are trying to adapt the retention parameters or to tune our queries. SQL> show parameter undo; NAME TYPE VALUE ———————————— ———– —————————— temp_undo_enabled boolean FALSE undo_management string AUTO undo_retention integer 3600 –extended from 900,…
By Franck Pachot . If you follow this blog, you should know how I like Orachrome Lighty for Oracle, for its efficiency to monitor database performance statistics. Today Orachrome released the beta version of Lighty for Postgres: https://orachrome.com/news/la-beta-de-lighty-for-postgresql-est-ouverte/ The Cloud is perfect to do short tests with more resources than my laptop, especially the predictability of performance, then I started…
This article is an additional article to my precedent about “SQL Server 2017: What’s happens with an interruption during a Resumable Online Index Rebuild?” The goal is to see after I suspend the rebuild, if I can run a traditional rebuild without the option RESUME. I start an index rebuild with the option Resumable: ALTER INDEX [NCI_dbo_Transaction] ON [dbo].[Transaction]…
Last week, I presented this option in our internal event, the dbi xChange. My colleague David Barbarin asked me this question, what’s append if an interruption occurs (reboot, SQL Server service stopped,…) during a Resumable Online Index Rebuild? I was not able to answer because I forgot to do this test. The new enhancement for an index rebuild provides the…
When doing a performance review I often do talk with the DBA about the CPU utilization of the server. How reliable is the server CPU utilization with tools like top or the host CPU utilization in the AWR-report? E.g. on an Linux Intel x86-64 server with 8 Cores and 16 logical CPUs (Intel Hyperthreading), what does a utilization of 50%…
This blog post draws on the previous article about index seek and gotchas. I encountered another interesting case but it is not so much because of the nature of the problem I decided to write this article but rather the different ways that exist to troubleshoot it. Firstly, let’s set the scene: A simple update query and its corresponding execution…
