Now Unachievable Certificate OCM Cloud

Finally, I’ve successfully achieved Oracle Certified Master, Database Cloud Administrator.

Here are the steps for Certified Oracle Database Masters:

  1. Hold an Oracle Database 11g/12c Administrator Master Certification
  2. Hold either the Oracle Real Application Clusters 11g and Grid Infrastructure Administrator Expert Certification
    or
    Oracle Exadata Database Machine Administrator Expert Certification
  3. Pass the exam Oracle Database Cloud Administration (1Z0-028) But Exam is already retired in May 2017. Those who have already cleared (more...)

License High Water Mark in Alert Log

License High Water Mark in Alert Log

The message was originally intended to let you know the maximum number of users sessions were used between bounces so that you could check this against how many sessions you were licensed for.

[root@localhost ~]# cat /u01/app/oracle/diag/rdbms/orcl/orcl/trace/alert_orcl.log |grep high
License high water mark = 169

You can query the V$LICENSE data dictionary view for the high water mark, it is a sessions_highwater column. Also, the current limits (more...)

Managing Remote Archived Log File Retention

In the previous article of Automatic deletion of archived redo log, we have seen automatic deletion is enabled by default in the Logical Standby database.

Automatic Deletion of Redo Log Files by SQL Apply

LOG_AUTO_DEL_RETENTION_TARGET parameter is responsible for this. It has default value 1440 minutes. However, we can manage this parameter and set retention for deletion of archive logs as per our requirement.

This parameter is only applicable if ‘LOG_AUTO_DELETE’ of dbms_logstdby.apply_set is (more...)

Automatic Deletion of Redo Log Files by SQL Apply

Archive log files which are used by SQL apply process at Logical Standby database is said to be Foreign Archive Logs or Remote Archived Logs. Foreign Archive log files are managed by SQL Apply process.

To know more about it Oracle Dataguard

After all the redo entries of Archive log files are applied using SQL apply process, these files are kept for a specific amount of time, a time set for LOG_AUTO_DEL_RETENTION_TARGET or for 1440 (more...)

Securing Your Logical Standby Database

The logical standby database is in Read-Write mode means a fully updatable mode. A database can be accessed and potential data may be changed. So Oracle data guard provides a lock. We can configure GUARD on the database at a different level according to our requirement.

Logical Standby Database Creation

A user access can be controlled with GUARD.

We can enable GUARD with ALTER DATABASE GUARD [ALL | STANDBY | NONE] command.

There are three (more...)

Setting Protection Modes in Dataguard

In this article, we will see parameters that we can set while setting different protection modes and its impact on primary database and standby database.

Protection modes in Oracle Dataguard

We have already seen Protection Modes in Data Guard Protection modes in Oracle Dataguard

Now let us see Redo Transport Attributes required for setting different protection mode.

1. Maximum Availability

  • AFFIRM OR NOAFFIRM

We can set AFFIRM and NOAFFIRM with Maximum Availability.

AFFIRM: When we (more...)

Logical Standby Database Creation

In the previous article, we have seen Preparation and consideration we need to see before creating Logical Standby Database.

Preparing to Create a Logical Standby Database

We can use following steps to create Logical Standby Database.

Prerequisites : Physical Standby database already created.

Step 1: Check Physical Standby Database is created and is synchronized with Primary Database.

Primary Database :

SQL> select name,open_mode,database_role from v$database;

NAME	  OPEN_MODE	       DATABASE_ROLE
--------- -------------------- ----------------
MGR	  READ WRITE	       PRIMARY

(more...)

Enabling Block Change Tracking on a Physical Standby Database

As with 11g Oracle comes with a new feature for Oracle Data Guard: Active Data guard. And with Active Data Guard enabled we can use Block Change Tracking feature for the physical standby database.

Now, what is Block Change Tracking?

Block Change Tracking: RMAN change tracking feature for incremental backups improves incremental backup performance by recording changed blocks in each datafile in a change tracking file. If change tracking is enabled, RMAN uses the change tracking file to (more...)

Role Transition Switchover and Failover

In Data Guard environment your database operates in one of two Role.

1.Primary Database

2.Standby Database.

To know more about it Oracle Dataguard

You can have Physical, Logical or Snapshot database in Standby role. Primary and Standby roles are mutually exclusive.

With Data Guard role management service we can change this role dynamically and can achieve our requirement.

There are two types of Role Transition possible.

1. Switchover : 

A switchover is planned (more...)

Preparing to Create a Logical Standby Database

Prior to that, we need to create the Physical Standby.

Logical Standby Database : SQL Apply Architecture

We need to perform following steps before creating Logical Standby Database :

1. Primary Database must be in Archive log mode.

Check your database is in archive log mode or not. If not enable it for archive log.

SQL> SELECT NAME,OPEN_MODE,LOG_MODE,DATABASE_ROLE FROM V$DATABASE;

NAME	  OPEN_MODE	       LOG_MODE     DATABASE_ROLE
--------- -------------------- ------------ ----------------
MGR	  READ WRITE	       ARCHIVELOG   PRIMARY

2. Unsupported (more...)

GDPR : The good, the good and the good!

As is the way with reporting these days, most of the posts about GDPR that have gained any sort of traction over the last few years/months/days have been focused on the doom and gloom side of things. I too have found myself focussing on this side of the issue, being the natural worrier that I am. Having said all that, I think it’s really important to take a step back and look at the issue (more...)

This is GDPR Reality

How many updated policies for use of personal data did you sign off the last couple days? As I had observed the EU procrastinating on their compliance for General Data Protection Regulations, (GDPR) until December of 2016, (it went into effect in April, 2014 with a deadline in the EU of December, 2016) I wasn’t surprised that we’re seeing a flurry of requests to sign off on data usage this week. The deadline is tomorrow, (more...)

A re-introduction to the vagrant-builder suite for database installation

In a blogpost introducing the vagrant builder suite I explained what the suite could do, and the principal use, to automate the installation of the Oracle database software and the creation of a database on a virtual machine using vagrant together with ansible and virtual box.

This blogpost shows how to use that suite for automating the installation of the Oracle database software and the creation of a database on a linux server directly, with (more...)

Show parameter

Just a quick little tip for Friday afternoon.

If you use the “show parameter” or “show spparameter” commands from SQL*Plus you’ve probably noticed that the parameter value may be too long for the defined output column, and even the parameter name may occasionally be too long. For example (from 12.2.0.1):

SQL> show spparameter optimizer

SID	 NAME			       TYPE	   VALUE
-------- ----------------------------- ----------- ----------------------------
*	 optimizer_adaptive_plans      boolean
*	 optimizer_adaptive_reporting_ boolean
	 only
*	 optimizer_adaptive_statistics boolean
 (more...)

Hybrid Columnar Compression in 12.2 – nice new feature

Oracle 12.2 introduced an interesting optimisation for Hybrid Columnar Compression (HCC). Until 12.2 you had to use direct path inserts into HCC compressed segments for data to be actually compressed. If you didn’t use a direct path insert you would still succeed in entering data into the segment, however your newly inserted data was not HCC compressed. There is no error message or other warning telling you about that, which can lead to (more...)

Missing Audit

Here’s a detail I discovered a long time ago – and rediscovered very recently: it’s possible to delete data from a table which is subject to audit without the delete being audited. I think the circumstances where it would matter are a little peculiar, and I’ve rarely seen systems that use the basic Oracle audit feature anyway, but this may solve a puzzle for someone, somewhere, someday.

The anomaly appears if you create a referential (more...)

Riga Dev Days

In about a week I’ll be at Riga Dev Days 2018 in Latvia.

It’s a very diverse event, covering a whole bunch of technologies over the three days, which includes a workshop day and the two conference days.

There is an Oracle track, so if that’s your thing you will find it there, but there’s also a bunch of different technologies discussed too, so there’s something for everyone. Check out the schedule here.

See you (more...)

Sneak Preview of pgio (The SLOB Method for PostgreSQL) Part IV: How To Reduce The Amount of Memory In The Linux Page Cache For Testing Purposes.

I hope these sneak peeks are of interest…

PostgreSQL and Buffered I/O

PostgreSQL uses buffered I/O. If you want to test your storage subsystem capabilities with database physical I/O you have to get the OS page cache “out of the way”–unless you want to load really large test data sets.

Although pgio (the SLOB Method for PostgreSQL) is still in Beta, I’d like to show this example of the tool I provide for users to (more...)

exachk 18.2.0_20180518 released

Oracle released the new Version of exachk. The version is shown as 18.2.0_2018052018 so far so good. The next sentence in the Note is: „What’s new in exachk 12.2.0.1.4 may be found in the „What’s New in 12.2.0.1.4″ section of the User’s Guide available here..“

The new Release model from Oracle is really confusing. From my point of view it makes no sense that you download (more...)

Users, schemas & privileges in #Exasol

Exasol Logo

In Exasol, a database user may own multiple schemas – or even none at all. I connect to my Community Edition to show that:

C:\Users\uh>cd \Program Files (x86)\EXASOL\EXASolution-6.0\EXAplus

C:\Program Files (x86)\EXASOL\EXASolution-6.0\EXAplus>exaplusx64 -c 192.168.56.101:8563 -u sys -p exasol -lang EN

EXAplus 6.0.8 (c) EXASOL AG

Wednesday, May 23, 2018 3:28:29 PM CEST
Connected to database EXAone as user sys.
EXASolution 6.0.8 (c) EXASOL AG

SQL_EXA>  (more...)