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Account locking in an Active Data Guard environment

During the Data Guard round table of the excellent UKOUG Tech18 conference I got aware of this topic that I’d like to share with the Oracle community:

What is the locking behavior for user accounts in an environment where users may connect to the primary as well as to the standby database?

Enhanced “validate” commands in Oracle’s Data Guard Broker 18c

If you are using an Oracle Database Enterprise Edition chances are that there is at least one environment in your estate making use of Data Guard. And if you are using Data Guard, why not use the broker? I have been using Data Guard broker for a long time now, and it has definitely improved a lot over the first releases, back in the day. I like it so much these days that I feel hard done by if I can’t make use of it. This is of course a matter of personal preference, and I might be exaggerating a little :)

One of the nice additions to the broker in Oracle 12.1 was the ability to validate a database before a role change. This is documented in the Data Guard broker documentation. I certainly don’t solely rely on the output of the command, I have my own checks I’m running that go over and above what a validate can do.

Creating a RAC 12.1 Data Guard Physical Standby environment (3b)

Huh, what is this I hear you ask? Part 3b? Oracle 12.1? Well, there’s a bit of a story to this post. Back in December 2016 I started to write a series of blog posts (part 1 | part 2 | part 3 | part 4) about how I created a standby database on RAC 12.1. For some reason I forgot to post this part. Up until now the step where I am creating the broker configuration was missing. Thanks to a friend I discovered my mistake.

Data Guard: always set db_create_file_dest on the standby

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:

Multitenant, PDB, ‘save state’, services and standby databases

Creating – and using – your own services has always been the recommendation. You can connect to a database without a service name, though the instance SID, but this is not what you should do. Each database registers its db_unique_name as a service, and you can use it to connect, but it is always better to create your own application service(s). In multitenant, each PDB registers its name as a service, but the recommendation is still there: create your own services, and connect with your services.
I’ll show in this blog post what happens if you use the PDB name as a service and the standby database registers to the same listener as the primary database. Of course, you can workaround the non-unique service names by registering to different listeners. But this just hides the problem. The main reason to use services is to be independent from physical attributes, so being forced to assign a specific TCP/IP port is not better than using an instance SID.

Little things worth knowing: redo transport in Data Guard 12.2 part 2

In the first part of this article I looked at a number of views and some netstat output to show how redo is transported from the primary database to its standby systems. The long story short is that TT02 (“async ORL multi”) was found sending redo to CDB3 asynchronously whilest NSS2 (“sync”) transferred redo to the synchronised target – CDB2. Unlike v$dataguard_process wanted me to believe, it really wasn’t LGWR sending redo over the network.

In this little article I would like to show you how the standby databases CDB2 and CDB3 receive redo and how you can map this back to the primary database, closing the loop.

Archivelog deletion policy on Data Guard configuration

The deletion policy on a dataguard configuration should be:

CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY;
for the site where you don’t backup. It can be the standby or the primary.

and:

CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY BACKED UP 1 TIMES TO DISK;
for the site where you do the backups. It can be the primary or the standby.

I’ve always configured it in this way, but I recently discovered that the order of the subclause matters. Do not CONFIGURE ARCHIVELOG DELETION POLICY TO BACKED UP 1 TIMES TO DISK APPLIED ON ALL STANDBY; because no archivelogs will be reclaimable, and your recovery area will be full. This is probably a bug. I’ll update this post when I have more information about this.

Display Data Guard configuration in SQL Developer

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 Q2 and the version number has more digits to mention the exact build time. Here this version is labeled 17.2.0.188.1159 and we can see when it has been built:

SQL> select to_date('17.x.0.188.1159','rr."x.0".ddd.hh24mi') build_time from dual;
 
BUILD_TIME
--------------------
07-JUL-2017 11:59:00

orapwd gives OPW-00029 Password complexity failed in #Oracle 12.2

https://uhesse.files.wordpress.com/2017/06/complex1.png?w=600&h=508 600w, htt