Oracle database management, tutorials, scripts, coding, programming and tips for database administrators
Timestamp with Oracle Time Zone columns exhibits 'interesting' behavior with respect to unique indexes and primary keys. Read on to see the issue and one possibly confusing way to handle it!
Recently Oracle has updated its JSON functionality in the database and that may present unexpected issues. Read on to see what changed and how it could affect results.
Transactions using NOLOGGING can make a database unusable if recovery is necessary. Read on to see why and how to protect the database from unrecoverable transactions.
Does a single-column primary key need a histogram? That may not be as silly of a question as might appear. Read on to find out why.
Changes in the way Oracle sets the flag value for the UNDO tablespace in version 12.x make the output from DBA_TABLESPACE_USAGE_METRICS either incomplete (12.1) or missing (12.2). Read on for more information.
With Oracle's Automatic Memory Management the spfile is updated with some interesting settings. Read on to see what the settings are and what they do.
IBM’s machine learning is being used to improve the performance of analytical queries as well as operational queries and their associated applications. This requires management attention, as you must verify that your business is prepared to consume these ML and AI conclusions. Learn more…
Whether it's a bug or by design Oracle's 1000-element in-list restriction isn't always enforced. Read on to see what conditions can bypass this limitation.
A look at ten top databases fighting for mind-share in 2019.
It's common practice to use UNION when joining result sets from different tables, but there may be times when that isn't the best choice. Read on to see why.
Standby databases are used in most, if not all, Data Recovery configurations, and init.ora files and control file creation scripts are usually generated on the primary. Read on to see why, when using Oracle Managed Files, they need to be created on the standby.
Oracle provides two ways to create an index that can reliably be used with nulls; a bitmap index and a function-based index. In this article, you will learn when each is applicable and see them in action!
Occasionally a join using primary key columns in a query can be eliminated because of the data involved. In Oracle 12.2 and later, multi-column primary keys can be used to do this; however, there are cases where the join elimination is not complete . In this article, you'll see an example that illustrates these points.
Oracle DBAs should know how Oracle behaves and should also be able to address issues without the aid of a flashy graphical user interface (or GUI). Are you a DBAs who would be lost without applications interfaces to help you with tasks?
iOracle version 12 introduced the hybrid histogram as a performance improvement. Learn about a change in Oracle 18 that can cause histograms to break.