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Oracle Parallel Query: Did you use MapReduce for years without knowing it?

By Franck Pachot . I’ve read this morning that MapReduce is dead. The first time I heard about MapReduce was when a software architect proposed to stop writing SQL on Oracle Database and replace it with MapReduce processing.

Linux: how to monitor the nofile limit

By Franck Pachot . In a previous post I explained how to measure the number of processes that are generated when a fork() or clone() call checks the nproc limit. There is another limit in /etc/limits.conf – or(…)

SQL Server: How to find the default data path?

I have read a lot of SQL Server blog postings and articles in order to find the default data path. This post covers different SQL Server versions (SQL Server 2012, SQL Server 2014, SQL Server 2008, SQL Server 2005)(…)

SQL Server 2014: sys.dm_exec_query_profiles, a new promising feature

Among the hidden features provided by SQL Server 2014 there is a very interesting dynamic management view named sys.dm_exec_query_profiles. This feature will help the database administrators and experienced developers to troubleshoot long running queries in real-time. I’m pretty sure(…)

Linux: how to monitor the nproc limit

By Franck Pachot . You probably know about ‘nproc’ limits in Linux which are set in /etc/limits.conf and checked with ‘ulimit -u’. But do you know how to handle the monitoring and be alerted when you’re close the fixed(…)

SQL Server 2014: Availability groups failover impossible with Failover Cluster Manager

A couple of weeks ago, I worked for a customer that wanted to implement SQL Server 2012 (and not SQL Server 214) AlwaysOn with availability groups. During our tests we performed a bunch of failover tests and the customer(…)

How to list all Oracle system schemas

By Franck Pachot . Do you want to know which users come with the Oracle Database and which are the ones you have created? This is that not easy, especially prior to Oracle 12c. You know SYS and SYSTEM,(…)

How to avoid Failover Cluster with PowerShell scripting

One of my colleague asked me some days ago if I could create a PowerShell script to get rid from Windows Server Failover Cluster. The reason is that it has, in some specific cases, the bad habit to failover(…)

Configure a Kerberos Client and Alfresco as a Kerberized application

In the previous blog, I described How to install and manage a Kerberos Server but that’s useless if there are no clients and if no application have been kerberized! That’s why in this blog I will explain in(…)

Oracle Exadata – poor optimization for FIRST_ROWS

By Franck Pachot . In a previous blog, I discussed the difference between rownum and row_number(), in particular their behaviour in implicitely adding a first_rows(n) to the optimizer. That reminded me that I forgot to blog about an(…)