Exadata - Poor optimization for FIRST_ROWS
In a previous blog, I discussed about the difference between rownum and row_number(), especially about their behaviour to add implicitely a first_rows(n) to the optimizer. That reminded me that I...
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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...
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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...
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SQL Server 2014: Availability groups failover impossible with Failover...
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...
View ArticleLinux: how to monitor the nproc limit
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...
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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...
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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...
View ArticleHow to list all Oracle system schemas
Do you want to know which are the users that come with the Oracle Database, and which are the users you have created? That's not easy, especially before 12c. You know SYS and SYSTEM, but there are many...
View ArticleLinux: how to monitor the nofile limit
In a previous post I explained how to measure the number of processes that account when a fork() or clone() call checks the nproc limit. There is another limit in /etc/limits.conf - or in /etc/limits.d...
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Oracle Parallel Query: Did you use MapReduce for years without knowing it?
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...
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Understanding JVM Java memory leaks
Lots of people think that Java is free of memory management as the JVM uses a Garbage Collector. The goal of this collector is to free objects that are no longer used in the program without the...
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Java Mission Control 5.2 (7u40) deserves your attention
Recently, some new versions of java were made available. Most people think Java updates are boring and only security-oriented. But one of the last updates (7u40) includes a feature which deserves...
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SQL Server 2014: Are DENY 'SELECT ALL USERS SECURABLES' permissions...
SQL Server 2014 improves the segregation of duties by implementing new server permissions. The most important is the SELECT ALL USERS SECURABLES permission that will help to restrict database...
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Master Data Services installation for SQL Server 2012
This posting is a tutorial for installing Master Data Services on your Windows Server 2012. Microsoft SQL Server Master Data Services (MDS) is a Master Management product from Microsoft, code-named...
View ArticlePartial Join Evaluation in Oracle 12c
Do you think that it's better to write semi-join SQL statements with IN(), EXISTS(), or to do a JOIN? Usually, the optimizer will evaluate the cost and do the transformation for you. And in this area,...
View ArticlePerfmon does not start automatically
I have recently used perfmon (performance monitor) at a customer site. I created a Data Collector Set to monitor CPU, Memory, Disk, and Network during one day. Then, I ran the monitor and I received a...
View ArticleOracle EM agent 12c thread leak on RAC
In a previous post about nproc limit, I wrote that I had to investigate the nproc limit with the number of threads because my Oracle 12c EM agent was having thousands of threads. This post is a short...
View ArticleBackup an SQL Server database from On-Premise to Azure
SQL Server database backup & restore from On-Premise to Azure is a feature introduced with SQL Server 2012 SP1 CU2. In the past, it could be used with these three tools: Transact-SQL (T-SQL)...
View ArticleBeyond In-Memory, what's new in 12.1.0.2 ?
It's just a patchset. The delivery that is there to stabilize a release with all the bug fixes. But it comes with a lot of new features as well. And not only the one that has been advertised as the...
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SQL monitoring 12.1.0.2 shows adaptive plans
In a previous post I've described Adaptive Plans. Even if I prefer to show plans with the SQL Monitor active html format, I had to stick with the dbms_xplan for that because SQL Monitoring did not show...
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