Natalka Roshak's blog
Submitted by Natalka Roshak on Sun, 2006-03-05 18:00
External Tables let you query data in a flat file as though the file were an Oracle table. In 9i, only read operations were permitted; in 10g, you can also write out data to an external table, although you can't write to an existing table.
Submitted by Natalka Roshak on Sun, 2006-02-12 18:00
There have been two high-profile Oracle security flaws in the last few months. The first, which everyone reading this article has probably heard of, is the Voyager worm. The second, which is slightly less well-known, is a very severe security hole that lets anyone with a valid logon to an Oracle database -- including an unprivileged account with nothing but CONNECT privs -- execute arbitrary code as SYS. In this article, I'll look at the two security flaws and outline the steps you need to take to protect your databases from them.
Submitted by Natalka Roshak on Sun, 2006-01-15 18:01
10gR1 revamped Oracle clustered database management and features. 10gR2 builds on this success with a long list of improvements and enhancements. Oracle has streamlined the installation process and provided more filesystem options, made some performance and monitoring improvements, and improved manageability with a half-dozen administration enhancements. This article will take a look at the major changes.
Submitted by Natalka Roshak on Thu, 2005-12-01 23:55
Just about every DBA has had to deal with ora-1000 errors, "Maximum open cursors exceeded." This article will discuss initialization parameters that affect open cursors, the difference between open and cached cursors, closing cursors, and monitoring open and cached cursors.
Submitted by Natalka Roshak on Sun, 2005-11-06 18:00
Everyone knows the basic features of sql*plus, but one underused feature that can make your scripts an order of magnitude more useful is the ability to store and reuse values, including values read from the database, in variables. This lets you use user-defined and database values not just in subsequent queries, but also in calls to other scripts and SQL*Plus's other functionality.
Submitted by Natalka Roshak on Sun, 2005-10-09 19:00
One of the primary tests for DBMS reliability is what's known as the ACID test. ACID-compliant systems are as close as you can get to guaranteed not to lose your data. Essentially, as long as your database files are intact, you are guaranteed that your data is consistent. This is not true for non-ACID compliant systems. Non-ACID-compliant systems are vulnerable to data inconsistency, and generally aren't taken seriously for any application where data integrity is important. Now, in 10gR2, Oracle offers us the option to break its ACID compliance.
Submitted by Natalka Roshak on Sun, 2005-09-11 19:00
DML error logging is a new feature for 10gR2. Have you ever tried to update 30 million records, only to have the update fail after twenty minutes because one record in 30 million fails a check constraint? Or, how about an insert-as-select that fails on row 999 of 1000 because one column value is too large? With DML error logging, adding one clause to your insert statement would cause the 999 correct records to be inserted successfully, and the one bad record to be written out to a table for you to resolve.
Submitted by Natalka Roshak on Sat, 2005-08-20 01:00
Oracle recommends that RAC databases be managed with srvctl, an Oracle-supplied tool that was first introduced with 9i RAC. The 10g version of srvctl is slightly different from the 9i implementation. In this article, we will look at how -- and why -- to manage your 10g databases with srvctl.
Submitted by Natalka Roshak on Wed, 2005-07-20 01:00
DBAs wanting to create a 10g Real Applications Cluster face many configuration decisions. One of the more potentially confusing decisions involves the choice of filesystems. Gone are the days when DBAs simply had to choose between "raw" and "cooked". DBAs setting up a 10g RAC can still choose raw devices, but they also have several filesystem options, and these options vary considerably from platform to platform. Further, some storage options cannot be used for all the files in the RAC setup. This article gives an overview of the RAC storage options available.