Wednesday, February 13, 2013

Oracle 12c Database

If we go by the announcements made by Oracle’s Larry Ellison, Oracle’s latest version of database (expected name is Oracle 12c database) is about to be released within few days/weeks. By the time world is awaiting the official launch, we thought of gathering the bits and pieces of information available about Oracle 12c database, just to get started with what can be expected from this so called Cloud optimized database version of Oracle. Here are some quick talking points as available on different websites (reference links provided).

Faster and Efficient
  • "First multi-tenant database in the world." 12c is what Ellison (Larry Ellison, CEO, Oracle) calls a "container database." It's function is to hold lots of other databases, keeping their data separate, but allowing them to share underlying hardware resources like memory or file storage.
  • With 12c, Ellison promises that Oracle databases will get faster, saying that compared to the current database, Oracle 11, 12c "uses one-sixth as much hardware and runs five times as many databases."
  • The new hardware version (Exadata x3) can run a mind-boggling amount of data in memory in real time.  With this new hardware you "can ask a question and get an answer at the speed of thought," Ellison said. Ellison claims that with x3, enterprises won't need to buy traditional storage from companies like EMC or Hitachi anymore.

Easy, Convinent and Resource Friendly
  •  Database 12c also makes much more efficient use of hardware resources, saving companies money, Mendelsohn (Andy Mendelsohn, Senior vice VP, Oracle) said. For example, it incorporates a "heat map" feature that tracks how frequently different chunks of data are used, allowing customers to archive rarely accessed information on lower-cost mediums.
  • Database upgrades and patches are made simpler than in the past thanks to the pluggable database concept, Mendelsohn said. "When you [patch] that one container database, you effectively patch all of them."
  • Backup and recovery efforts benefit as well, allowing administrators to back up the system as one unit but recover at the pluggable database level.

Appliance based 
  • A new Exadata Database Machine to be announced (now already announced) at Open World will undoubtedly exploit the database virtualization capabilities of the 12c database.

Besides these, there are also some information snippets about the new auto-optimizer feature, that would change the way databases work: 
Oracle Database Optimizer: An Insider’s View of How the Optimizer Works

Oracle database 12c is the first step on the way to making an adaptive, or self-learning optimiser.

Alternative subplans are precomputed and stored in the cursor, so no new hard parsing will be needed as part of the adaption of an already executing plan. Statistics collectors are included in the plan execution. If the collectors cross a threshold, the plan might switch during execution from a nested loops to a hash join.

Information gathered by the optimizer, may prompt automatic creation of column groups, so next time stats are gathered, the extended stats will be gathered.

But besides these direct factors about Oracle 12c, there are some more facts that could frame some more pieces about the estimated wire-frame. 
Oracle Cloud: Oracle had recently launched its own clouds, and the new database version should be in full sync with these clouds. And as name already suggests, Oracle 12c (here 'c' stands for cloud) would be a cloud optimized product, and might be readily available for the cloud users in form of pre-configured machines (as provided by AWS).

Acquisitions:  Recent acquisitions of Taleo, SelectMinds,  Collective Intellect, Eloqua, Virtue etc. suggests that Oracle is planning to develop its own stack of cloud-based applications. In future not so far, Oracle might be planning to provide cloud based CRM or ERP apps to compete against its current major threat SAP HANA. 

A proper validation/confirmation of this information can be made with the official release from Oracle, but from the information available so far, it seems that Oracle is planning to launch something big. Oracle, as a market leader in databases, is facing lots of expectations from its customers, and since Oracle has taken good time to launch its next release of database, it must be planning for a good surprise not only for its own customers, but also for its competitors.


Tuesday, February 12, 2013

When I traveled through time using SAP HANA!!

(This blog first appeared on SCN website

When I traveled through time using SAP HANA!!

Yes! SAP HANA can make time travel happen. Literally!!

During our exploration of SAP HANA, we found that SAP has made time travel possible via SAP HANA. This is because SAP HANA runs on SAP In-Memory Computing Engine, which provides support for History Tables. These tables, known as 'HISTORY COLUMN' tables, have session type as ‘HISTORY’ and they support time travel queries.

‘Time travel’ queries are the queries against historical states of the database. In a way, it allows to fetch the historical values (say, some inventory statistics for date 1 Jan 2011 in the table CURRENT_INVENTORY), without actually having to load the data from backups taken on 1 Jan 2011.

This concept (and specially this emotional touch of TRAVELLING through time) caught us, and we ended up exploring this concept in the following manner. All the steps and information sources were duly documented, so that other interested enthusiasts can also enjoy this experience in their own labs.

Following is the basic procedure for using Time Travel Queries in SAP HANA:
  1. Create History Tables
  2. Turn Auto Commit Off
  3. Keep track of commit IDs (or connection IDs) dealing with the History tables
  4. Execute Time Travel Queries on the History Tables


For demonstration purposes, implementing time travel seems to be bit easy task. But in real life scenarios, implementation would be much more complex, and would demand entire new set of plans and designs for fully utilizing this new concept.
We would love to hear more about real life scenarios where this concept could make a real difference. So do provide your feedback and suggestions about this topic.


·         0204 - Modeling - Time Travel Example.pdf, available as a zipped content at

Tuesday, February 5, 2013

SQL Server Learning Tree

We are working towards developing a Center of Excellence around Application Platform and Database technologies. For the efforts, in continuation to my previous blog on SQL Server Learning framework, we are planning to work on preparing a complete SQL Server Learning Tree. This would be a generic learning framework, covering the most common topics irrespective of any version number, but assuming the latest version information in case of any conflicts. This tree has many branches (i.e. areas of SQL Server that we want to explore more, like deployment, operations, management etc.). Each branch will have several leaves (the topics to read, like for deployment branch, we can have installations, setup, configuration etc.). A rough sketch for such tree is already prepared as a startup.
Would like inputs on making this more versatile and adaptable to different categories of people having various expertise levels.

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