Oracle database management, tutorials, scripts, coding, programming and tips for database administrators
Oracle can still have issues with ANSI join syntax, producing sub-optimal translations and possibly wrong results. Read on to see how Oracle processes ANSI join syntax and how that translation process can create some problems.
In Oracle 22.214.171.124 shared cursor memory in some subpools can increase dramatically over time, resulting in having to restart the database. Read on to see how this was discovered and how to check the subpool memory allocations.
SQL*Loader can fail to load LOB data when function-based indexes are present on the LOB columns. Read on to learn more and work around the issue.
Using the utlrp.sql script when Edition-based Redefinition is enabled can cause the recompile process to terminate with an ORA-00600 error in 126.96.36.199. Read on to see why this can happen.
Oracle 188.8.131.52 can throw an ORA-01438 when importing an interval partitioned table. Read on to learn a work-around until Oracle patches the bug.
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.