Everything our consultants learn while running databases for customers: Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, MongoDB and Delphix. Expect hands-on posts about installation, day-to-day administration, backup and recovery, performance tuning, replication and upgrades.
Today I faced a strange issue when I tried to install a new SQL Server instance : Failed to retrieve data for this request This error occurred just after clicking on “New SQL Server stand-alone installation…” The error message is not helpful at all. So, the first step to troubleshoot an issue is to look at the error logs. The…
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…
I’m doing some cleaning on my customer’s instances. I want to delete the login of a previous DBA for 2 reasons; this person does not work anymore in my customer’s company and all DBA are members of a group that is given permission on the instances. I don’t want to see any DBA’s personal login on SQL Server instances. When…
A new release of MySQL was out on July 13 (8.0.21). Among all the changes, there are some that I have already tested and that I really appreciate. Who stopped the MySQL server? In previous releases, I can already see in the error log file who stopped the MySQL server if this was done through the shutdown statement. In MySQL…
InfluxDB InfluxDB is a powerfull open source time series database (TSDB) developped by InfluxData. It’s a database optimized for time-stamped or time series data. Time series data are simply measurements or events that are tracked. It is particully interresting for metric tracking like server cpu, ram, application performances and so on. It is similar to SQL databases but different in…
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…
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…
Introduction Before the freshly come “workload manager” feature on latest Control-M versions, the Control-M users used a lot of workarounds to manage the workload execution. Using Quantitative resources was one of the most used. Request We need to trigger a workflow on demand without having to hold the jobs or release them manually. For example, launch it and stop it…
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,…
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…
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:…
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…
