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Category Archives: Database Administration & Monitoring

David Barbarin

SQL Server 2016 : tempdb database enhancements in CTP 2.4

By | Database Administration & Monitoring | 2 Comments

The new CTP 2.4 has been released and announced by Microsoft in its blog post a couple of days ago. During my investigation, I noticed some new  installer capabilities about the tempdb database. As a reminder, you can read my first thoughts from my blog post here, but to be short, the installer was able to provide automatically the right number of data files according to the number of existing CPUs and the best practices…

 
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Oracle Team

Query V$UNDOSTAT for relevant time window

By | Database Administration & Monitoring, Oracle | 2 Comments

By Franck Pachot . When you have a query failing in ‘ORA-01555: snapshot too old: rollback segment number … with name … too small’ you have two things to do: Convince the developer that the rollback segment is not too small because the message text comes from old versions Find information about query duration, undo retention and stolen blocks statistics. This is the goal of this post  

 
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Stéphane Haby

Row Level Security (RLS) is also coming to MS SQL Server

By | Database Administration & Monitoring, Technology Survey | No Comments

Why “also” in my title? On 29 August, my colleague Daniel Westermann wrote an article about Row Level Security in the next version of PostgreSQL. Row Level Security called also RLS is a new feature in SQL Server 2016 and of course in SQL Azure. This new security in SQL Server returns only rows that the user has permission to access. The best way to understand is with a little sample and I use Daniel’s…

 
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Stéphane Savorgnano

SQL Server 2016: Transaction Performance Analysis Overview & In-Memory OLTP Migration Checklists

By | Database Administration & Monitoring | No Comments

To be able to define which Tables or Stored Procedures will us the best performance gain after migration to In-Memory OLTP, SQL Server 2014 provided a tool called AMR (Analysis Migration and Reporting). This tool was really interesting but we should have, before to use it, to create a Management Data Warehouse and so on… (I wrote a blog here for this configuration and an article on SQL Magazine here) With SQL Server 2016, actually…

 
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David Barbarin

SQL Server 2016 : availability groups with no domain dependencies

By | Database Administration & Monitoring | No Comments

Are you aware about the new features of the next Windows version? Currently we’re in TP3 and during my investigation, I was very happy to see the new features for Windows clustering (cf. this blog post from Microsoft). By reading this article we can see: Workgroup Clusters: Clusters with nodes which are member servers / workgroup (not domain joined) If you remember, Microsoft had introduced Active Directory-Detached Cluster feature with Windows 2012 but the dependency…

 
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Daniel Westermann

SEVERE:OUI-10020:The target area /u01/app/oracle/oraInventory/ is being used as a source by another session

By | Database Administration & Monitoring | No Comments

What to do if you get the above error when you try to install Oracle SE2 (did not test if the same issue is there with EE, but probably it is) in silent mode?: ./runInstaller oracle.install.option=INSTALL_DB_SWONLY \ ORACLE_BASE=/u01/app/oracle/ \ ORACLE_HOME=/u01/app/oracle/product/12.1.0/db_2_4/ \ UNIX_GROUP_NAME=oinstall \ oracle.install.db.DBA_GROUP=dba \ oracle.install.db.OPER_GROUP=dba \ oracle.install.db.BACKUPDBA_GROUP=dba \ oracle.install.db.DGDBA_GROUP=dba \ oracle.install.db.KMDBA_GROUP=dba \ FROM_LOCATION=../stage/products.xml \ INVENTORY_LOCATION=/u01/app/oracle/oraInventory/ \ SELECTED_LANGUAGES=en \ oracle.install.db.InstallEdition=SE2 \ DECLINE_SECURITY_UPDATES=true -silent -ignoreSysPrereqs -ignorePrereq -waitForCompletion You already checked my oracle support and verified that…

 
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Oracle Team

Do you use SQL Plan Baselines?

By | Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . I can hear a lot of complaints about the instability coming from the adaptive features introduced into the optimizer logic at each release. Giving more intelligence to the optimizer is very good to improve the response time for generated queries, BI, ad-hoc reporting. But when you have an OLTP that works for years with its static set of queries, then you don’t appreciate the plan instability coming from (in reverse chronological…

 
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David Barbarin

SQL Server AlwaysOn : readable secondary replicas and index rebuild online vs offline

By | Database Administration & Monitoring | 2 Comments

A couple of weeks ago, I was involved in a discussion on the French forum developpez.com about SQL Server AlwaysOn and availability groups, index strategies and the impact on the readable secondary replicas. During this discussion, one of the forum member stated that rebuilding an index online had less impact than rebuilding an index offline on a readable secondary replica but I disagree with this affirmative. Is it really true? Let’s verify in this blog…

 
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Oracle Team

You are in Standard Edition One? Don’t worry.

By | Database Administration & Monitoring, Oracle | 23 Comments

By Franck Pachot . You want the amazing features of Oracle SQL and PL/SQL with minimal cost. Your database is too large for Oracle XE edition, but not big enough to require the cost of Enterprise Edition. You accept to do things manually, have maintenance windows. You are ok with a RTO of 5 minutes (time to switchover with Dbvisit standby), RPO of 10 minutes (archive_lag_target=600). Your servers have no more than 2 sockets. So…

 
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