Submitted by Lalit Kumar B on Fri, 2014-09-05 05:27
It's a lazy Friday and I saw an interesting question in Stack Overflow about "Why are there two “null” keywords in Oracle's v$reserved_words view?" And I spent next 2 hours digging into knowing the reason. Here are my findings:
We need to understand how to interpret the view v$reserved _words. To determine whether a particular keyword is reserved in any way, check the RESERVED, RES_TYPE, RES_ATTR, and RES_SEMI columns.
Submitted by John Watson on Sun, 2014-08-31 10:17
How much undo and redo does Oracle generate for different operations? More than you might think.
Submitted by John Watson on Sat, 2014-07-19 10:39
Buffer busy wait and related events can cripple performance of concurrent inserts. Bad in a single instance database, far worse in a RAC (think "gc buffer busy"). Often the problem is because of a primary key populated from a sequence. Reversing the index can fix this problem.
Submitted by John Watson on Sun, 2014-07-06 06:02
Concurrent inserts into a table will often result in crippling buffer busy wait problems as sessions serialize on access to the last block(s) of the table segment. Using hash clusters can remove the issue.
Submitted by rleishman on Wed, 2014-07-02 06:04
After more than 20 years of working with Oracle databases, I have recently found myself using SQL Server for the very first time. Until now, I have been a passive observer in the My-Database-Is-Better-Than-Yours wars, so it’s a pleasant change to be able to finally contribute.
Submitted by John Watson on Sun, 2014-06-08 11:55
Many people are terrified of global indexes, one reason being that partition DDLs on the table will either render them unusable, or take forever as they are updated. Deferred global index maintenance solves this, and should be an important driver for the 12c upgrade.
Submitted by John Watson on Wed, 2014-06-04 19:56
Why use interpreted PL/SQL when native compiled PL/SQL is so much faster? No reason at all - except that interpreted is the default, and most DBAs never change this. They should.
Submitted by John Watson on Sun, 2014-05-11 06:16
Can this parameter really boost performance? This simple test suggests that it can.
Submitted by John Watson on Sat, 2014-05-10 06:28
Unified Audit is a major architectural change: fast, easy, and impossible for the DBA to bypass. On upgrade to Oracle 12c, you really should enable it. The earlier method that we all use is pretty awful.
Submitted by Lalit Kumar B on Sat, 2014-05-03 09:48
It is a frequently asked question in almost all the Oracle forums. There have had been numerous questions/posts regarding "But how to generate the trace file?" Well, it might seem a heck of a task, however, looking it step by step will make you understand that it is actually not that difficult.
Usually, database application developers do not have the required/necessary permissions/privileges to do all the steps that I will mention below. However, most of the steps could be done by application developer. A few steps will need a DBA privilege.