How does SELECT * FROM TABLE find its data? Back to basics with datafiles, segments and extents
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 comes running a basic SELECT statement to scan a table - how does the database locate your data? Catch me on twitter https://twitter.com/connor_mc_d if you have questions.