Infrastructure at your Service

David Barbarin

SQL Server 2014: In-Memory tables, Bw-Tree, and storage

By | Database management | No Comments

SQL Server 2014 introduces hash indexes with in-memory optimized tables. I described some of their aspects in a previous blog post.  These indexes are very efficient with lookup search operations but have some limitations with operations like range scans, inequality predicates or scan order operations. These limitations are linked to hash index design that stores rows in the index in a random order. Fortunately, nonclustered indexes for in-memory optimized tables (aka range indexes or Bw-Tree)…

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Oracle Team

Oracle TNS_ADMIN issues due to bad environment settings

By | Database management | 2 Comments

Recently, I faced a TNS resolution problem at a customer. The reason was a bad environment setting: The customer called the service desk because of a DBLINK pointing to a bad database. The users were supposed to be redirected to a development database, and the DBLINK was redirecting to a validation database instead. The particularity of the environment is that development and validation databases are running on the same server, but on different Oracle homes, each…

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Oracle Team

Oracle 12c Adaptive Plan & inflection point

By | Database management, Oracle | One Comment

By Franck Pachot . The Oracle 12c Adaptive Plan feature was already presented by Nicolas Jardot in OOW 2013: Solving customer issues with the 12c Optimizer. I recently had to answer several questions about its behavior at execution time. Maybe the term ‘adaptive’ is misleading. It’s not that a join will stop and restart to another join method. Even with adaptive plan there will only be one join method to be applied. The feature only…

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Morgan Patou

How to install and manage a Kerberos Server

By | Application integration & Middleware | 5 Comments

For some time now, I have been working on how to set up a Single Sign-On (SSO) solution in my company. As a big fan of Open Source solutions, I have obviously proposed the implementation of a solution based on Kerberos. What I mean by that is a solution based on the true Kerberos, i. e. MIT Kerberos. Indeed, Kerberos was originally a research project at the Massachusetts Institute for Technology (MIT) in the early…

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Oracle Team

Best practice for the sending of an Oracle execution plan

By | Database Administration & Monitoring, Oracle | 5 Comments

By Franck Pachot . You have a query that takes too long and you want help to analyze the execution plan? Then you need to get it with relevant information, and correctly formatted. Autotrace is not a good option as it does not bind the variables in the same way as your application. Explain plan only shows estimations, but if we have a performance issue, this probably means that the estimation is wrong. I prefer…

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Morgan Patou

Kerberos SSO with Documentum D2 3.1 SP1

By | Application integration & Middleware | 4 Comments

Last week, when I was working on how to setup the Kerberos SSO for D2 3.1 SP1, I faced some issues due to a documentation that doesn’t seem to be up to date… In fact, our version is D2 3.1 SP1 and there is no specific documentation for SP1. In consequence, I read the D2 3.1 Installation Guide and the D2 4.0 Installation Guide. The first time I read the D2 3.1 documentation, I found…

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David Barbarin

Transparent data encryption, key management and backup strategies

By | Database management | 7 Comments

Transparent Data Encryption requires the creation of a database key encryption. The database key is a part of the hierarchy of SQL Server encryption tree with at the top of the tree the DPAPI. Then if we traverse the tree from the top to bottom we can find the service master key, the database master key, the server certificate or the asymmetric key and finally the database encryption key (AKA the DEK). In this hierarchy…

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Oracle Team

The consequences of NOLOGGING in Oracle

By | Database management, Oracle | No Comments

By Franck Pachot . While answering to a question on Oracle forum about NOLOGGING consequences, I provided a test case that deserves a bit more explanation. Nologging operations are good to generate minimal redo on bulk operations (direct-path inserts, index creation/rebuild). But in case we have to restore a backup that was made before the nologging operation, we loose data. And even if we can accept that, we have some manual operations to do. Here…

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Alain Lacour

Oracle APEX: redirect all pages to one

By | Application integration & Middleware | 2 Comments

This blog will explain how to proceed in order to redirect all the application pages to one single page, prior to their processing and rendering, with Oracle APEX 4.0 and above. In some cases, like security checks, you may want to redirect all calls of any page in your APEX application to one single page whith particular processing before the target page is rendering or even processing. I ran into this need again, recently while…

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David Barbarin

SQL Server 2014: Buffer pool extension – an interesting new feature

By | Database management | One Comment

Buffer pool extension (aka BPE) is an interesting feature of SQL Server 2014. Database administrators already know that memory is one of the key assets available for SQL Server. This is especially true for buffer pool memory, which plays an important role in storing data page and reducing the I/O demand. Nowadays, even if the memory has become cheaper, we are often facing limitations such as mid-size hardware configurations and increasing memory. All this can…

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Oracle Team

Investigating Oracle lock issues with event 10704

By | Database management, Oracle | 3 Comments

By Franck Pachot . Did you ever encounter unexplained Oracle lock issues? They may be coming from unindexed foreign keys (which is worse in 11g). It’s not easy to monitor. Of course you can check Oracle locks from V$LOCKED_OBJECT, but that is a solution only for locks that remain. Some Oracle locks are there only for a short duration. How do you check which lock is acquired by a statement? Event 10704 is the solution. I’ll show…

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Oracle Team

Troubleshooting: ORA-29283 when oracle is member of a group with read/write privileges

By | Database management | 6 Comments

Recently, I worked on an Oracle database migration for a customer and I faced a strange behavior when accessing a file stored on the file system of the Oracle database. The database has been migrated on a new server, and consolidated with existing databases. Several jobs are running into the database and need to access the file system to read or write some files. A particular file is received daily from a remote job over…

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