Infrastructure at your Service

David Barbarin

SQL Server: DBCC CHECKDB does not detect corruption

By | Database management | 3 Comments
 

 During my audits at customer places, it still happens very often to find SQL Server databases with page verification option configured to “none”. I always alert my customers on this configuration point because it can have an impact on the overall integrity of their databases. One of my customer told me that the integrity task of its maintenance will detect the corruption anyway and alert him by email – but is it really the case?…

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Pierre Sicot

PostgreSQL for Oracle DBAs – an introduction

By | Database management | One Comment
 

  Having worked for several years as an Oracle DBA, I decided to have a look at the PostgreSQL database and see how it functions in comparison to the Oracle Database. The “Enterprise DB” graphical installation of PostgreSQL 9.3 is quite easy and rather fast. Under Linux you run the graphical installer, dialog boxes lead you through the installation process. You enter the specific information of your system and at the end of the PostgreSQL…

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David Barbarin

SQL Saturday in Paris on 12 -13 September

By | Database management | No Comments
 

  As you certainly know SQL Saturday events are very popular in SQL Server world community. This is the second time the event takes place in Paris (France), but this time, we have a new format with pre-conferences on Wednesday and classic sessions on Saturday. During pre-conferences, we will talk about a particular subject for a whole day. This time, I have the opportunity to participate twice by giving two sessions (in French) with the following…

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Franck Pachot

PDB media failure may cause the whole CDB to crash

By | Database management, Oracle | 3 Comments
 

 Do you remember last year, when 12c arrived with multitenant, David Hueber warned us about the fact that a single PDB can, under certain conditions, generate a complete system downtime? We are beta testers and opened a SR for that. Now one year later the first patchset is out and obviously I checked if the issue was fixed. It’s a patchset afterall, which is expected to fix issues before than bringing new features. So the…

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Franck Pachot

SQL monitoring 12.1.0.2 shows adaptive plans

By | Database management, Oracle | No Comments
 

 In a previous post, I have 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 all information about adaptive plans. This has been fixed in the Patchset 1 and I have run the same query to show the new feature. First, an adaptive plan can be in two states: ‘resolving’ where all…

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Franck Pachot

Beyond In-Memory, what’s new in 12.1.0.2 ?

By | Database management, Oracle | No Comments
 

 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 future of the database. It’s a huge release. Let’s have a look at what’s new. First, it seems that it will be the only patchest for 12.1 Then, there is that In-Memory option awaited for…

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Nathan Courtine

Backup a SQL Server database from On-Premise to Azure

By | Hardware & Storage | No Comments
 

 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) PowerShell SQL Server Management Objects (SMO) With SQL Server 2014, backup & restore can also be enabled via SQL Server Management Studio (SSMS). Concept This feature is quite similar to a “classic” backup & restore tool. Indeed, the main different lies in…

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Franck Pachot

Drilling down V$RECOVERY_AREA_USAGE

By | Database management, Oracle | 2 Comments
 

 In a previous post I used X$KCCAGF to get more information about reclaimable archived logs in FRA, because there is a bug in standby (not opened) databases where archivelog deletion policy is ignored. I explained that the view V$RECOVERY_AREA_USAGE has only aggregated information about space reclaimable without the details about which files are reclaimable or not. Here I’ll explain how I came to X$KCCAGF and I’ll give the query to get all the detailed information…

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Franck Pachot

Oracle EM agent 12c thread leak on RAC

By | Database management, Oracle | 4 Comments
 

 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 feedback about this issue and the way I have found the root cause. It concerns the enterprise manager agent 12c on Grid Infrasctructure >= 11.2.0.2 NLWP The issue was: ps -o nlwp,pid,lwp,args -u oracle | sort -n…

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Stéphane Haby

SQL Server Perfmon does not start automatically

By | Application integration & Middleware | No Comments
 

 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 “beautiful” error message… What happened? Ok, to be sure that it was not a rights or a setting problem in my Data Collector Set, I tried with a System Data Collector Set and got the same error. I read…

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Franck Pachot

Partial Join Evaluation in Oracle 12c

By | Database management, Oracle | One Comment
 

 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, one more transformation has been introduced in 12c which is the Partial Join Evaluation (PJE). First, let’s have a look at the 11g behaviour. For that example, I use the SCOTT schema, but I hire a lot more employees…

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Nathan Courtine

Master Data Services installation for SQL Server 2012

By | Database management | One Comment
 

  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 Bulldog. It is the rebranding of the Stratature MDM product, titled +EDM and acquired in June 2007 by Microsoft. Initially, it was integrated for the first time in Microsoft SQL Server 2008 as an additional installer. But since SQL Server 2012, Master Data Services…

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