Oracle Zero Data Loss Recovery Appliance

In DBA, Oracle database, Oracle Engineered Systems, RMAN on October 30, 2014 at 17:57

During the early versions of Oracle, Larry Ellison was asked once if anyone ever asked for their money back. His answer was: “No, but they used to ask us for their DATA back.”


Backup and Recovery go hand-in-hand, right? It is just that before recovery, we need to restore the data under the solid assumption that there is something to restore.

From the 10 member family of Oracle Engineered Systems, the ZDLRA is in my opinion the most critical. Let me explain why including some useful information for system DBAs.


Granted we do not want to find solutions to problems we don’t have, let us look at what DBAs’ reality is today. Most problems listed below are not longer just DBA’s weekly burdens, they affect global business directly:

1. Data growth and long backup windows: system is slow and virtually unusable because of a long running backup, what are the options now: offload backups to an ADG site, use BCV splits, do not take backups at all?

2. Infinite availability: looks like people do not talk any more of four 9s or five 9s, more and more often I hear words like zero down time, infinite availability, continuous availability. An ex-colleague and friend of mine used to say: “Zero downtime exists only in power point presentations”.

3. Lack of backup validation and end-to-end visibility: according to the Oracle documentation, the main purpose of RMAN validation is to check for corrupt blocks and missing files. You can also use RMAN to determine whether backups can be restored. How often do we do that? Really!

4. Data loss and data corruption: one can write a book on this subject. I still sadly witness databases being backed up using storage replication. That is indeed a very fast way to backup corrupted data blocks!

Recovery Appliance provides the following benefits:

1. Elimination of Data Loss
2. Minimal Backup Overhead
3. Improved End-to-End Data Protection Visibility
4. Cloud-Scale Protection

Here is a sample picture of the Recovery Appliance Architecture (it is worth reading the details behind the link):


Core DBAs might be interested in the new DBMS_RA package. A DBA can use the DBMS_RA subprograms to perform all Recovery Appliance administration functions. Check the DBMS_RA Package Reference.

There 27 new views related to the ZDLRA. Check the Recovery Appliance View Reference for more details.

The database account RASYS owns the Recovery Appliance schema, which includes the RMAN recovery catalog and the DBMS_RA PL/SQL package. The RASYS user name is fixed and cannot be changed. RASYS does not have the privileges required to create database user accounts.

DBAs should know that the Zero Data Loss Recovery Appliance Backup Module is an Oracle-supplied SBT library that RMAN uses to transfer backup data over the network to the Recovery Appliance. An SBT library transfers data to and from a backup device type, either a tape device or Recovery Appliance. RMAN performs all backups to the Recovery Appliance, and all restores of complete backup sets, by means of this module.

The Recovery Appliance Backup Module must be installed in the following two locations: (1) in the ORACLE_HOME of every protected database that sends backups to a Recovery Appliance for Recovery Appliance replication environments, and (2) on every upstream Recovery Appliance that sends backups to downstream Recovery Appliances.

Another important new concept for DBAs is the protection policy one: it is a named collection of properties that you can assign to multiple protected databases. A default installation of Recovery Appliance has these 4 protection policies.

Finally, an important questions: which databases are supported? The following Oracle Database releases are:

    - Oracle Database releases 10.2 through require manual HTTPS configuration.
    - Oracle Database releases and 12.x are fully supported.

Four good links to start from:

1. Zero Data Loss Recovery Appliance Administrator’s Guide Release 12.1
2. Reinventing Database Protection
3. Data Sheet – Oracle Zero Data Loss Recovery Appliance
4. A Technical Guide to Oracle’s Recovery Appliance


Oracle Database New Features

In Database options, DBA, Oracle database on July 23, 2014 at 14:25

Oracle Database was released yesterday, July 22nd 2014.

I found no issues whatsoever with downloading, installing the software and creating a container database plus enabling the in-memory option.


Here are few useful links:

1. Oracle Database Software Download
2. Oracle 12cR1 Documentation
3. MOS 1905806.1 about
4. Oracle Database Blog: is available!!!

When you setup the IM option, note the inmemory area specified in the output below:

SQL> startup
ORACLE instance started.

Total System Global Area  838860800 bytes
Fixed Size		    2929936 bytes
Variable Size		  511707888 bytes
Database Buffers	   50331648 bytes
Redo Buffers		    5455872 bytes
In-Memory Area		  268435456 bytes
Database mounted.
Database opened.
SQL> show parameter inmemory

NAME				     TYPE			       VALUE
------------------------------------ --------------------------------- ------------------------------
inmemory_clause_default 	     string
inmemory_force			     string			       DEFAULT
inmemory_max_populate_servers	     integer			       1
inmemory_query			     string			       ENABLE
inmemory_size			     big integer		       256M
inmemory_trickle_repopulate_servers_ integer			       1
optimizer_inmemory_aware	     boolean			       TRUE

Let me show you how one can see the incredible speed of the inmemory option:

SQL> alter table SALES inmemory;

Table altered.

SQL> select max(price) most_expensive_order from sales;


Elapsed: 00:00:02.50

SQL> alter session set inmemory_query="DISABLE";

Session altered.

Elapsed: 00:00:00.03

SQL> select max(price) most_expensive_order from sales;


Elapsed: 00:01:25.51

Check the following new commands and views related to the in-memory option:

SQL> alter table SALES inmemory memcompress for capacity high;

Table altered.

SQL> alter table SALES no inmemory (client);

Table altered.

SQL> select segment_name, inmemory_size, inmemory_compression, bytes/inmemory_size comp_ratio from v$im_segments;

-------------------- ------------- ------------------------------ ----------
SALES			  24969216 FOR CAPACITY HIGH		  11.6325459

SQL> select table_name, cache, inmemory_compression comp, inmemory_priority priority, inmemory_distribute RAC from dba_tables where table_name = 'SALES';

------------ ---------- -------------------- ---------- ----------

SQL> select view_name from dba_views where view_name like 'V_$IM%';


10 rows selected.

Some of the most interesting new features are:

Oracle Database In-Memory
In-Memory Aggregation and In-Memory Column Store
Oracle Big Data SQL
Advanced Index Compression
Automatic Big Table Caching
Zone Maps for full table access
New and optimized SQL function, APPROX_COUNT_DISTINCT()
Full Database Caching
Rapid Home Provisioning based on gold images stored in a catalog of pre-created homes
New database parameter: DBFIPS_140


ORAchk replaces EXAchks and RACcheck

In Database tuning, DBA, Oracle utilities on June 21, 2014 at 12:48

The new tool from Oracle ORAchk includes EXAchks and RACcheck functionality and replaces the older tools. It is no longer just a database tool but also runs health check on E-Business Suite Financials, Enterprise Manager Cloud Control repository, GoldenGate and Sun Systems.


Going memory lane, have a look at how Statspack compares with BSTAT/ESTAT. Well, those days are long over. DBAs used to have their own scripts, ran their own healthchecks but some special scripts can still shed some more light on the system health.

One such example is Tanel Poder’s Exadata Snapper.

For details on the ORAchk tool, how to download it, what’s new in ORAchk, read MOS Note 1268927.2. If you do not have access to MOS, here are 2 blog posts that describe the tool quite well:

1. ORAchk Health Checks for the Oracle Stack (including Solaris) by Gerry Haskins

2. ORAchk Health Checks For The Oracle Stack by Levi Pereira

Here is how System Health Score is calculated:


I would recommend glancing first at the ORAchk Known Issues before starting using the tool: MOS 1509746.1

Note that ORAchk’s requirements are as follows:

Supported Platforms:
Linux x86-64* (Enterprise Linux, RedHat and SuSE 9, SuSE 10 and SuSE 11)
Oracle Solaris SPARC (Solaris 10 and 11)
Oracle Solaris x86-64 (Solaris 10 and 11)
AIX **

* 32-bit platforms not supported, no planned support for Linux Itanium
**Requires BASH Shell 3.2 or higher to be installed

Supported Oracle Releases:

Still, no Windows…

And, do not aim at a 100% score, you will not get it easily. Points get deducted if you have more than 1 instance on the server:

WARNING OS: Multiple RDBMS instances discovered, observe database consolidation best practices

According to the tool, there is a “risk for shared resource contention leading for instability, performance degradation or scalability problems”. Then it says: “if the database consolidation best practices have already been reviewed and observed then this message can be ignored”.

Not to mention that you might run the report twice in a row and get a different score.

But there is more: ORAchk Collection Manager is a companion application to ORAchk, RACcheck and Exachk. When having lots of systems, auditing them with ORAchk might be a tedious piece of work. ORAchk has long had the ability to upload the results of its audit checks into a database automatically at run time.

However, it was up to us to create a custom front-end to that data for reporting purposes and trend analysis. Now, with ORAchk Collection Manager, Oracle provides this Application Express application to be used as a dashboard in which they can track their ORAchk, RACcheck and Exachk collection data in one easy to use interface.

Download the ORAchk Collection Manager and go through the ORAchk Collection Manager Users Guide for more details.


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