Understanding UNDO

Sooner or later, every Oracle DBA will hit a problem of some sort that is related to the concept of Oracle “Undo”. The Oracle Undo performs a few very important functions in the database; these being the support of read-consistent queries and Flashback queries, supporting transactions (COMMIT and ROLLBACK), and recovering from database crashes. Along […]

postgreSQL, mysql, and Oracle

Although my main interest is in the venerable Oracle database as database administrator and as a programmer over the past 17 years or so, at the same time I have been following along with the progress of the various open-source databases as well with quite a keen interest. The two that I’ve been mainly following […]