You have lot of db links between two databases, you think they are not used but want to be sure. It’s not difficult. When doing distributed transactions (which means running a transaction that involves remote databases through db links) the SCN of the database is synchronized. Comparing them can help. But let’s explain that.
All posts by Franck Pachot
When we give our trainings (dbi services workshops) we signal our best practices with this logo. It’s our know-how, acquired through experience, consulting, service desk, exchange at events, beta testing, etc. that we share with our customers. Let’s have a look at a few points that we recommend to change if you provision a database with DBaaS on the Cloud.
You don’t want to reload the datawarehouse database every night. And you may want to have it refreshed more often, in real-time during the day. There is another reason to capture all changes from the operational database: you want the history of all updates and not only the current value. This is why you use change Data Capture (and Streams propagation is based on that), a feature available in Enterprise Edition with no need of…
My first trial was not very good because I had access to Schema as a Service only. Which is not new. But Oracle Cloud Services is becoming now a reality, available for trial and available for general availability. Let’s see now how to use Database as a Service.
Yes, the topics for the OCM 12c upgrade are online and I’m already looking at the topics. I’m talking about the ‘Configure the Resource Manager’ one here. Configuring Resource Manager in commandline is not easy. At the OCM exam you can do things faster when you have a GUI. Of course, you need to know where to find the command line API in case no GUI is available. In 11g, even if no Cloud Control…
In the part I we have seen the properties that are imported when you add a database to the configuration, and which are then managed by the broker. Now we will list the properties that are managed by the broker, but whose default value is not imported from the instance parameters.
When I passed the OCM 11g exam, I had to prepare the ‘Manage Materialized Views to improve rewrite’ topic. Now that I’m preparing the 12c upgrade I checked quickly what I’ve prepared… and it doesn’t work. This post is about query rewrite, a bug in 12c, how to understand why it doesn’t rewrite, and how rewrite is accepted when constraints are not enforced and when materialized view is stale.
When you are using the DataGuard Broker, you should always use the broker (with DGMGRL or OEM) to change the parameters that are managed, rather than changing them with ALTER SYSTEM. But do you know which parameters are concerned? I’ve divided the parameters in two parts. All are set by the broker, but only some of them are read when you add a new database to the configuration.
The result cache is very nice when base tables are static: get the result without any buffer get, without any join or sorts. But as soon as any DML occurs on one of the tables the result is based on, then result cache is invalidated. And cache misses are quite expensive. You can think of it as a materialized view in memory. But with materialized views, you can accept to see stale results in order…