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Oracle Team

MERGE JOIN CARTESIAN: a join method or a join type?

By | Oracle | No Comments

By Franck Pachot . I’ll present about join methods at POUG and DOAG. I’ll show how the different join methods work in order to better understand them. The idea is to show Nested Loops, Hash Join, Sort Merge Join, Merge Join Cartesian on the same query. I’ll run a simple join between DEPT and EMP with the USE_NL, USE_HASH, USE_MERGE and USE_MERGE_CARTESIAN hints. I’ll show the execution plan, with SQL Monitoring in text mode. And…

 
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Oracle Team

How much free space can be reclaimed from a segment?

By | Oracle | No Comments

By Franck Pachot . You have the feeling that your table takes more blocks than it should? Here are the queries I use to quickly check the free space. The idea is to call DBMS_SPACE.SPACE_USAGE and infer the minimum space from the percentages. For example, a block in FS3 (defined as having at least 50 to 75% free space) is supposed to have at least 50% of free space. Of course it can have more,…

 
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Oracle Team

Oracle 18c preinstall RPM on RedHat RHEL

By | Oracle | No Comments

By Franck Pachot . The Linux prerequisites for Oracle Database are all documented but using the pre-install rpm makes all things easier. Before 18c, this was easy on Oracle Enterprise Linux (OEL) but not so easy on RedHat (RHEL) where the .rpm had many dependencies on OEL and UEK. Now that 18c is there to download, there’s also the 18c preinstall rpm and the good news is that it can be run also on RHEL…

 
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Jérôme Dubar

Patching ODA lite to 12.2.1.4.0

By | Database Administration & Monitoring, Database management, Oracle | No Comments

Here is how to apply the latest patch for your ODA. As usual the Oracle documentation is not 100% accurate. I applied this patch on 2 ODAs X7-2M previously deployed in 12.2.1.2.0, no intermediate patch was needed. 1) Download the patch The patch number is 28216794. This patch will update the following components:  dcs (odacli), operating system, bios/firmwares, ilom, GI, dbhomes and databases. Download and copy the patch to a temporary folder on the server,…

 
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Marc Wagner

ODA, network interface and configure-firstnet

By | Database Administration & Monitoring | No Comments

Deploying new ODA X7-2S or 2M, I have been curious how configure-firstnet would interact with the fiber and copper ethernet network interfaces. Reading documentation on the web, I could not clearly understand if it is mandatory to have the ODA connected to the LAN when performing an ODA reimage and/or running the configure-firstnet in additionnal of having ILOM connection. After digging deeper and few tests, I wanted to share my experience in this blog.  

 
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Oracle Team

Release 18.0.0.0.0 Version 18.3.0.0.0 On-Premises binaries

By | Oracle | No Comments

By Franck Pachot . Good news, the latest Patchset for Oracle 12cR2 (which is not named patchset anymore, is actually called release 18c and numbered 18.0.0.0.0) is available for download on OTN. It is great because OTN download does not require access to Support and Software Updates. It is available to anybody under the Free Developer License Terms (basically development, testing, prototyping, and demonstrating for an application that is not in production and for non-commercial…

 
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Petre Radut

Control File issues on duplicating with non patched Oracle version.

By | Database Administration & Monitoring, Oracle | No Comments

Introduction : RMAN has the ability to duplicate, or clone, a database from a backup or from an active database. It is possible to create a duplicate database on a remote server with the same file structure, or on a remote server with a different file structure or on the local server with a different file structure. For some old and  non patched Oracle versions such as that earlier than 11.2.0.4 , the duplicate (from…

 
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Clemens Bleile

Restarting a failed transportable tablespace metadata import

By | Database Administration & Monitoring | 2 Comments

I’m currently working in a project to migrate a Datawarehouse-database from Solaris to Linux Intel (Endian-change). We do use the cross platform incremental backups method as described in My Oracle Support Note 1389592.1 for that. I.e. incremental backups are applied to database files and during the migration the recovered datafiles are attached to the target database via the transportable tablespace method. When testing the transportable tablespace metadata import I got an error for a table:…

 
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Oracle Team

Data Guard: always set db_create_file_dest on the standby

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By Franck Pachot . The file name convert parameters are not dynamic and require a restart of the instance. An enhancement request was filled in 2011. I mentioned recently on Twitter that it can be annoying with Active Data Guard when a file on the primary server is created on a path that has no file name conversion. However, Ian Baugaard mentioned that there is a workaround for this specific case because db_create_file_dest is dynamic:…

 
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Oracle Team

18c: Order by in WITH clause is not preserved

By | Oracle | No Comments

By Franck Pachot . For a previous post I’ve run on 18c a script of mine to get the V$MYSTAT delta values between two queries. This script (new version available on GitHub) generates the queries to store some values and subtract them on the next execution. But I had to fix it for 18c because I relied on some order by in a CTE which is lost in 18c. The idea was to get the…

 
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