Infrastructure at your Service
By Franck Pachot . When you load data in direct-path and have the NOLOGGING attribute set, you minimize redo generation, but you take the risk, in case of media recovery, to loose the data in the blocks that you’ve loaded. So you probably run a backup as soon as the load is done. But what happens if you have a crash, with media failure, before the backup is finish? I encountered recently the situation but…
Since Oracle 10g, Oracle provides a great tool to import and export data from databases: Data Pump. This tool offers several helpful options, particularly one that allows to import data in a different tablespace than the source database. This parameter is REMAP_TABLESPACE. However, how can you do the same when you cannot use Data Pump to perform Oracle import and export operations? I was confronted with this issue recently, and I had to deal with…
By Franck Pachot . Recently, I described the Partial Join Evaluation transformation that appeared last year in Oracle 12c. I did it as an introduction for another transformation that appeared long time ago in 10.1.0.3 but was not used by default. And even in the latest Oracle 12c patchset 1 (aka 12.1.0.2.0) it is still not enabled. But it’s there and you can use it if you set optimizer_features_enabled to 12.1.0.2.1 (that’s not a typo!)….
While working on a customer project, I needed to retrieve the SQL Server SCOM Management Pack version. Unfortunately, the SCOM team took a while to answer and as I am the DBA, I have access to the SCOM databases. So let’s have a look at how we can get this the “hard” way. On 30/06/2014, a new Management Pack was published for SQL Server. I have installed the last package and a lot bugs were fixed…
Deploying an SQL Server database to a Windows Azure virtual machine is a feature introduced with SQL Server 2014. It can be useful for an organization that wants to reduce its infrastucture management, simplify the deployment, or have a fast virtual machine generation. Concept This new feature is a wizard which allows either to copy or migrate an On-Premise SQL Server database to a Windows Azure virtual machine. The following schema explains the main process…
In this blog post I want to sharing some useful DQL and IAPI queries that I am using all the time. They are more dedicated to Documentum support/debug and grouped by components. In order to use them, I recommend Qdman: it is the best tool I know to use DQL and IAPI scripts. 1. xPlore It regroups both the search engine and the index management. DQL Dsearch select * from dm_document search document contains ‘manual.doc’…
Have you noticed an interesting behavior with SQL Server 2014 when you are running a dbcc checkdb command? If not, you should have a look at this blog post. I discovered it completely by accident during some tests. If you watch carefully, you will see “weird” files appear while the dbcc checkdb command is running. Below is a sample of the file you will find near the corresponded database file: The file immediately disappears after…
By Franck Pachot . When an Oracle Database spends a high percentage of its DB time in User I/O, I usually check the wait event histograms in order to see if the storage system is working well. But today, with storage going to SSD, most I/O are less than 1 milliseconds and we have no details about those wait times. Here is what is exposed by V$WAIT_EVENT_HISTOGRAM: select event,wait_time_milli,wait_count from v$event_histogram where event like…
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?…
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 installation,…
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 program:…
By Franck Pachot . 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…
