The ROWID underpins many forms of data access within the Oracle Database. If you're a newcomer to Oracle, querying the rowid from a table returns a cryptic string such as "AAAhDyABAAABd0SAAA". But head back into the earlier versions of the database, and querying the rowid would return a completely different format like "0005DD12.0000.0040". In this episode, I'll cover what the rowid is, why the format of the...
A tablespace is just a logical grouping of files in your Oracle database. But behind that simple definition sits a remarkable evolution of how tablespaces are defined and managed internally. This episode covers the early days of tablespaces and the pitfalls with managing their space utilisation from within the data dictionary. Then we'll move into the changes and improvements that with Oracle 8i and 8i. Finally we cover some of...
The beauty of databases is they we just throw SQL at it, and it handles all the heavy lifting of working out where your data is, and how best to find it. But even for the novice, it is useful to know the fundamental mechanisms in which data is stored. In this episode, I cover datafiles, segments, extents and how your queries translate to the data physically stored on disk. Finally I'll go through how all of that applies when it...
On StackOverflow, I chanced upon a beginner being trolled as they struggled to get going with Oracle. "Duh! Just start the database" someone said dismissively. I called out the rudeness by replying: "You don't start a database, you start an instance". So lets go back to basics, and describe Oracle in its most fundamental terms: What is a database? What is an instance? And why its important to understand the diff...
The Spoken Nerd is all about database tech from Connor McDonald - a database tech who has spent 20+ years working with database tech! Ever being frustrated as a child with the limits of 1 KB of RAM in his Sinclair ZX80 computer, Connor has loved the challenges that come with storing data. When the infamous Y2K did not end the world as people thought, he started presenting at conferences and now in our virtual-dominated world, a...