An introduction to Oracle Database for beginners: What is a relational database management system?—Part I

Oracle provides a convenient virtual machine (VM) containing a complete and ready-to-use installation of Oracle Database 12c on Linux. All you need to do is to download and install the Oracle VirtualBox virtualization software and then import a ready-to-use VM.(read more)

An introduction to Oracle Database for beginners: What is a relational database management system?—Part III

What Is a Relational Database?

Relational database theory was laid out by Codd in 1970 in a paper titled “A Relational Model for Data for Large Shared Data Banks.” His theory was meant as an alternative to the “programmer as navigator” paradigm that was prevalent in his day.

In pre-relational databases, records were chained together by pointers, as illustrated in the following figures. Each chain has an owner and zero or more members. For (more...)

An introduction to Oracle Database for beginners: What is a relational database management system?—Part V

Physical Data Independence means that you and I shouldn’t have to worry about implementation details such as the storage structures used to store data.(read more)

An introduction to Oracle Database for beginners: What is a relational database management system?—Part IV

Database management systems such as Oracle are the interface between users and databases. Database management systems differ in the range of features they provide, but all of them offer certain core features such as transaction management, data integrity, and security. And, of course, they offer the ability to create databases and to define their structure, as well as to store, retrieve, update, and delete the data in the databases.(read more)

An introduction to Oracle Database for beginners: What is a relational database management system?—Part II

When you start thinking in terms such as security management, availability management, continuity management, change management, incident management, problem management, configuration management, release management, and capacity management, the business of database administration begins to make coherent sense and you become a more effective database administrator. (read more)

Believe it or Not: Converting an Inner Join to an Outer Join to improve performance

The cost-based optimizer tries to merge views whenever possible but sometimes we ma y want to override this behavior; that is, we may want the optimizer to push predicates into the view instead of merging the view into the main query. If the main query performs an inner join to the view, it becomes necessary to convert the inner join to an outer join if the database version is less than 12.1.0.2.(read more)

Happy Hinting: Undocumented PUSH_PRED hint variation

There isn’t a documented method of controlling which specific predicate to push.; it appears that the decision is left to the cost-based optimizer. However there is an undocumented method. Both the PUSH_PRED and NO_PUSH_PRED hints accept an optional second parameter(read more)

The Oracle Database professional I admire most

Carlos Sierra spent 17 years in the SQL performance group of Oracle Support. He couldn’t move a mountain nor pull down a big oak tree. But Carlos Sierra became a mighty big man by putting all the knowledge he gained during that time into a wonderful tool called “SQLT.”(read more)

Point to Ponder: The most important insight about Oracle Database upgrades?

Someone recently gave me an insight with which you would probably agree with: If query performance is satisfactory before and after the upgrade, then business users are unlikely to complain if new optimizer features are not being used after the upgrade.(read more)

Major and Minor keys in Oracle NoSQL Databsae

Oracle NoSQL Database uses Major and Minor key values to influence record co-location. Records are stored based on the hash of the major key, so all of the records with the same major key will be co-located on the same server.

A JSON document could be divided into sub-parts, with each sub-part having a different minor key. For example, customer meta data could be stored in the main customer record, transactions in a different record, (more...)

Oracle Cloud v/s Amazon Cloud?

A few years ago, I taught an online class in Oracle database administration for the University of Washington. Every student was given their own virtual machine for the duration of the class, courtesy of Amazon. It was ridiculously simple to clone, start, stop, and destroy virtual machines using the Amazon CLI (command line interface). All students had full SSH and SQL*Net access to their virtual machines in the Amazon cloud. At that time, Oracle had (more...)

NoSQL workshop at Oracle user group conference

Oracle NoSQL Database has been regularly featured at the conferences of the Northern California Oracle Users Group. But, at its most recent conference, the Northern California Oracle Users Group dared to play outside the Oracle sandbox with a whole day NoSQL workshop featuring three Oracle competitors: MongoDB, Couchbase, and Cassandra.(read more)

The best idea since 1992: Putting the C into ACID (We need your vote)

Oracle Rdb (only available for the VMS platform) supports SQL-92 assertions (http://community.hpe.com/hpeb/attachments/hpeb/itrc-149/22979/1/15667.doc) so why not Oracle Database? Let’s put the “C” into “ACID.”(read more)

When SQLT is not enough

A SQLT report has all kinds of pertinent information including—to name just a few—optimizer settings, indexes, statistics, plan history, and view definitions. However, sometimes a SQLT report is not enough to solve a SQL performance problem.(read more)

How is data modeled in NoSQL?

The important thing to understand is the data does not change just because it is managed differently. If the data does not change, then the entities and the relationships contained in the data cannot change either. The entities and the relationships between them have not changed since the dawn of time. They were the same in the days of network database management systems which came before relational database management systems, they stayed the same when (more...)

Why should Oracle Database professionals care about NoSQL and where to start?

Oracle Corporation openly admits that NoSQL database management systems have the performance advantage over relational database management systems “when data access is ‘simple’ in nature and application demands exceed the volume or latency capability of traditional data management solutions.” Database professionals should therefore look seriously at NoSQL technology.(read more)

Why Brian Hitchcock and I (probably) know more about Oracle Database than you‏

Brian Hitchcock’s secret is simple. For twelve years, he has been reading books on Oracle Database. And taking extensive notes. And publishing them in the NoCOUG Journal. My secret is simple. For twelve years, I have been reading the extensive book notes that Brian has been publishing in the NoCOUG Journal. I’m the editor of the NoCOUG Journal but that’s not the point. It’s that simple. (read more)

NoCOUG changes its name (Happy April Fools Day)‏

The board members of NoCOUG meets in closed session to discuss the continuing decline in memberships and conference attendance.(read more)

The company that is most responsible for NoSQL is not Amazon

The company that is most responsible for NoSQL is not Amazon but Oracle Corporation.(read more)

The First and Last Word on NoSQL

Amazon had the first word on NoSQL but the creator of relational theory, Dr. E. F. Codd, gets the last word.(read more)