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Oracle

Oracle Database as our consultants live it every day: installation and patching, upgrades, RMAN backup and recovery, Data Guard, RAC, performance tuning, multitenant, licensing, and engineered systems such as ODA and Exadata.

Oracle 18c RU and RUR for pioneers and followers

By Franck Pachot . In a previous post, I explained the announcement of the new release model, with Release Updates and Release Update Revisions replacing Proactive Bundle Patch and PSUs. Here is a description that will help you to plan your patching activity. Which DBA are you? There are currently a lot of discussions about the different types of DBAs.… 

“_suppress_identifiers_on_dupkey” – the SAP workaround for bad design

By Franck Pachot . In SQL, ‘upsert’ is a conditional insert or update: if the row is there, you update it, but if it is not there, you insert it. In Oracle, you should use a MERGE statement for that. You are clearly doing it wrong if you code something like: begin insert… exception when dup_val_on_index then update… end; But… 

Oracle Big Data Cloud Service – Compute Edition

In this blog post, we will see how to create a Big Data cluster through the Oracle Cloud Services. If you want more details about the Oracle Big Data cloud services offering, you can refer to my previous blog Introduction to Oracle Big Data. First, you need to create your trial account through the following link: https://cloud.oracle.com/tryit. Note that, when… 

Introduction to Oracle Big Data Services

Since few years, Oracle decided to move forward in the Big Data area, as their main competitor. The goal of this blog post is to explain you, how the Oracle Big Data offering is composed. As the Oracle Big Data offering is continuously improving, I’m always open to your feedback 🙂 Oracle Big Data offering is split in 2 parts:… 

When deterministic function is not

By Franck Pachot . When you declare a function-based index, the function is deterministic, which means that calling it with same arguments will always return the same result. This is required because the indexed values, which are the result of the function, are stored in the index. But what happens if you declare a function deterministic when it is not?… 

Using WebLogic 12C RESTful management for monitoring WebLogic Domains

WebLogic 12.2.1 provides a new RESTful management interface with full accesses to all WebLogic Server resources. This interface offers an alternative to the WLST scripting or JMX developments for the management and the monitoring of WebLogic Domains. The following of this blog provides a few examples demonstrating the simplicity and the efficiency of the REST requests. WebLogic Server State When… 

Am I a DBA 3.0 or just an SQL*DBA?

By Franck Pachot . There are currently a lot of new buzz words and re-namings which suggest that our DBA role is changing, most of them escorted with a #cloud hashtag. Oracle Technology Network is now called Oracle Developer Community. Larry Ellison announced the database that does not need to be operated by humans. And people talking about the death… 

Wrong result with multitenant, dba_contraints and current_schema

By Franck Pachot . Multitenant architecture is not such a big change and this is why I recommend it when you start a project in 12c or if you upgrade to 12.2 – of course after thoroughly testing your application. However, there is a point where you may encounter problems on dictionary queries, because it is really a big change… 

Active Data Guard services in Multitenant

By Franck Pachot . A database (or the CDB in multitenant) registers its name as the default service. When a standby database is on the same server, or same cluster, you have no problem because this database name is the db_unique_name which is different between the primary and the standby(s). In multitenant, in addition to that, each PDB registers its… 

12c Access Control Lists

By Franck Pachot . There is already enough information about the new simplified 12c way to define Access Control Lists, such as in oracle-base. I’m just posting my example here to show how it is easy. If, as a non-SYS user you want to connect to a host with TCP, you get an error: SQL> connect DEMO1/demo@//localhost/PDB1 Connected. SQL> SQL>… 

Create constraints in your datawarehouse – why and how

By Franck Pachot . We still see some developers not declaring referential integrity constraints in datawarehouse databases because they think they don’t need it (integrity of data has been validated by the ETL). Here is a small demo I did to show why you need to declare them, and how to do it to avoid any overhead on the ETL.… 

impdp content=metadata_only locks the stats

By Franck Pachot . With Oracle you can learn something every day. Today, preparing a migration to 12.2, I found all tables had locked statistics. I learned that it is the expected behavior since 10.2 when importing metadata_only including statistics, to avoid that the automatic job gathering comes and replaces the stats by ‘0 rows’. It is documented in DataPump…