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…
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…
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>…
By Franck Pachot . In my UKOUG OracleScene article on 12c online statistics and GTT I mentioned the following: A final note about those 12c changes in statistics gathering on GTT. In 11g the dbms_stats did a commit at the start. So if you did gather stats after the load, you had to set the GTT as ON COMMIT PRESERVE…
By Franck Pachot . Going to multitenant architecture is not a big change. The administration things (DBA, monitoring, backups) connect to the CDB and the application things connect to the PDB. Without the multitenant option, it is still recommended to go to the CDB architecture. The non-CDB is deprecated and the multitenant architecture brings interesting features. People often ask how…
By Franck Pachot . There are little changes when you go to multitenant architecture and one of them is that you must connect with a service name. You cannot connect directly to a PDB with a beaqueath (aka local) connection. This post is about a workaround you may have in mind: create a common user and set a logon trigger…
When working with WebLogic, there will probably be a moment when you will ask yourself: damn, what is wrong? Nowadays, software are so complex that it is kind of easy to introduce bugs/non-wanted behaviors in them… In this blog, I will present a small thing that just blew my mind when I faced it: I had a fully working WLS…
By Franck Pachot . The latest version of SQL Developer, the 17.2 one released after Q2 of 2017, has a new item in the DBA view showing the Data Guard configuration. This is the occasion to show how you can cascade the log shipping in Oracle 12c A quick note about this new versioning: this is the release for 2017…
By Franck Pachot . I described in an earlier post on AWR views how the dictionary views were using metadata and object links to show information from other containers. But this mechanism cannot work for fixed views (aka V$) because they don’t have their definition in the dictionary. The big difference is that most of V$ views are available long…
By Franck Pachot . Application Container brings a new way to share data among databases, and adds a new dimension to referential integrity. A foreign key in an application PDB can reference a row belonging to a root data link table. But then, should a delete on the root validate that there are no orpheans in the application PDBs? And…
By Franck Pachot . In a previous post https://www.dbi-services.com/blog/dataguard-wait-events-have-changed-in-12c/ I mentioned the new processes NSA for ASYNC transport and NSS for SYNC transport. I’m answering a bit late to a comment about the number of processes: yes there is one NSSn process per LOG_ARCHIVE_DEST_n destination in SYNC and the numbers match. Here is my configuration with two physical standby: DGMGRL>…
By Franck Pachot . Disclaimer My goal here is only to show that the Refreshable PDB feature works by shipping and applying redo, and then can synchronize a copy of the datafiles. I do not recommend to use it for disaster recovery in any production environment yet. Even if I’m using only supported features, those features were not designed for…
