Oracle database management, tutorials, scripts, coding, programming and tips for database administrators
New licensing for Oracle’s SE family line significantly lowers value to the enterprise.
RMAN in Oracle version 184.108.40.206 is sending incorrect information to the Tivoli MML process, resulting in backup files that are larger than expected, filling the storage pool and causing the backups to fail.
Extended statistics can provide better plans by recognizing correlated columns in a table. Oracle 12c makes those statistics easier by providing an automatic way to generate them. Read on to see how this can provide better plans.
Oracle's PL/SQL provides a results cache, and it works fairly well. Problems can arise when multiple sessions are using it. Read on to see what those problems are.
UNDO is a key part of any Oracle transaction, and Automatic Undo makes undo management easier for the DBA. Read on to see how it works and why most undo-related errors are a thing of the past.
If it weren't for the Hakan Factor, bitmap indexes wouldn't exist. Read on to see what the Hakan Factor is and how bitmap indexes use it.
Finding 'unused' indexes in Oracle isn't an easy task for a number of reasons. Read on to see why an index you might think isn't used probably is and discover the long path to dealing with such indexes.
Declaring a primary key isn't always easy, as some choices that look good at the start aren't the best choices when they're examined in depth. Read on to find out what data would make a good key, when to use a surrogate key and when to combine the two.
Delayed block cleanout can be frustrating when it generates errors. Read on to see what it is and what you can do about it.
The index property 'clustering factor' relies on the table data location, which is why rebuilding an index won't affect it. Read on to see what the clustering factor represents and how 'fixing' it for one index can make it worse for others created against the same table.
Over the years Oracle backup and recovery has changed significantly, from manual backups to the most recent version of RMAN. Read on to see where we were and where we are now.
Monitoring tablespace space is a constant, yet necessary, task. It's changed over the years and releases, so read on to see how it used to be done and what new views are available to make the task easier.
According to Jonathan Lewis: "Stoptimisation - the art of optimization by not doing the things you don't need to do." Read on to see what things you may be doing that you shouldn't be doing.
When using BULK COLLECT it's possible to see all of the exceptions thrown for the bulk collection by coding the exception handler properly. Read on to see how to implement such an exception handler.
NULL values in a table can cause Oracle to decide to use a Cartesian join with large data sets. Read on to see one way this can be addressed.