Oracle database management, tutorials, scripts, coding, programming and tips for database administrators
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.
Perl can sometimes 'misbehave' with the Oracle Enterprise Manager (OEM) agent for version 13c. Read on to see what issues it can create and how to correct them.
Oracle provides a method of encrypting networked database connections, with a few caveats. Read on to see how this is configured and what settings will ensure encrypted communication.
Sometimes the obvious isn't when it comes to query performance; that's when event 10053 can help. Read on to see how to use this event to tune query performance.
Oracle has provided a new setting, local_temp_tablespace, for RAC installations. Read on to see what this does and how it can end up being set incorrectly.
With some ports of Oracle 12.2, attempting to set ddl_lock_timeout at the session level can throw an ORA-00068. Read on to see one way this can be fixed.
Keeping data secure also means keeping it obscured should a breach occur. Read on to see how Oracle's Transparent Data Encryption can keep that data from prying eyes.
The cursor_sharing=force setting is designed to substitute system-generated bind variables for literals, but there are cases where not all literals are replaced. Read on to see when this can occur.
Many organizations are looking at the prospect of a technology migration, where capabilities are moved to a new set of technologies, supporting and enabling the business of the future. Anoop Kumar lays out the steps that can be followed to migrate an on-premise Oracle database to the SQL Server cloud database, Azure SQL Database.
Although documented, the ASCIISTR() function may return 'interesting' results depending on the characters translated. Read on to see what problems this can cause and a possible fix.
Using Oracle VM can be a fast and reliable way to create dev and test environments. Read on to see how this can be done and how it can help migrate databases from other operating systems.
Patching an Oracle installation can be interesting, especially if the patch needs to be backed out. Read on to see how to create a process that preserves the original home.
Since Solaris is soon to be unsupported the x86 platform may be a desirable choice. Read on to see how to make the transition easier.